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Equipment Discussions >> Mounts

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Hilmi
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ASA DDM60 Pro vs. GM1000HPS
      #6094580 - 09/22/13 06:55 AM

First of, I did not start this topic in order to start controversy. As I had mentioned earlier I am now saving up for a new mount and I have been looking at my alternatives. I already know the respective merits (and few shortcomings) of the Mach1GTO which are very well documented on the internet. On the other hand these two particular mounts have very little material on them available online (at least from what I could find). Most of the material I found is marketing material. I am trying to get feedback from people who have actually used these mounts at focal lengths similar to those a I am working at. I am currently working at 1680mm to 2000mm. I image with an STT-8300 which provides for a rather small pixel scale when not binned. I sometimes image with a DSLR, but mostly I use the CCD camera.

Therefore, keeping this in mind I am imaging with a laptop anyway, so bringing a laptop is not a big deal, I would like to know the experience (specifically for imaging at these focal lengths or higher) are. I am not too impressed when somebody tells me they can image at 600mm unguided. I can already image at short focal lengths unguided. I have no interest in short focal length imaging.

So far my limited research shows the following:

DDM60 Pro:
+Through the mount cabling
+Integrated laser pointer for rough alignment
+The ability to model tracking for the specific path of the object you are going to image
+Integrated USB hub and power connectors for accessories
-More expensive
-You have to sort out your own tripod
-100% computer dependent (no bigy but still a negative)

GM1000HPS
+Track satellites (not sure I would use this)
+Comes in a nice package that includes covers and carry bag and tripod (no need to hunt around for components to complete the package
+Works without computer (Nice to have, but not a must)
+Removable electronics
+Since the firmware is linux based, I am assuming that it is open to future 3rd party upgrades
-No through the mount cabling
-No polar alignment scope or laser for initial rough alignment

I will be spending a lot more money than last time. My last purchase did not meet my needs, I need to be ultra careful with my next purchase. That is not to say that I should stick to AP without any questions, I am willing to try other brands with their new interesting features, provided I find evidence to back that they are good enough to demand such a premium price tag.


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GIR
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Hilmi]
      #6094784 - 09/22/13 10:27 AM

Quote:

...I am not too impressed when somebody tells me they can image at 600mm unguided...




Well, maybe you should be because the basic principles for doing it well with longer FLs are very much the same


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Hilmi
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: GIR]
      #6094808 - 09/22/13 10:43 AM

The reason is I can image unguided at shorter focal lengths already. I can with my G11 already image for 40 minutes (Ha) unguided at 400mm focal length. Only reason I couldn't use the images was because some parts where over saturated. I have the images to prove it too. Yet I still have difficulty with 1680 mm

At close to 3 times the price I want to see far more than 20 minutes 600 mm.


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GIR
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Hilmi]
      #6094819 - 09/22/13 10:47 AM


Good luck with your research


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David PavlichAdministrator
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Hilmi]
      #6094852 - 09/22/13 11:09 AM

It seems from my readings of personal experiences here, the DDM series, once the quirks are conquered, is a top pick for unguided imaging for one reason; it is direct drive, no PE. At that point, it's up to you to get that polar alignment as close to perfection as possible.

However, I've seen some very impressive results with mounts not mentioned here, especially at the sub 1000mm focal length. APs, SBs, and a certain MI250 (not mine) that have done some outstanding unguided images at much longer focal lengths than 1000mm. But...these results come with added costs.

Add to that, your location, and then support becomes an issue. With that in mind, I'd stick with what is best for you in terms of service.

David


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Per Frejvall
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: GIR]
      #6094875 - 09/22/13 11:23 AM

10Micron firmware is NOT open source or available for modification in any way.

I have never missed a polar scope. All that is needed is a compass bearing, a quick aim and three stars. After that you do he initial adjustment.

In order to reach unguided performance with a single-axis tracking mount (like the Losmandy - I assume it does not offer dual axis tracking as it lacks encoders) the polar alignment must be second to none. I do not think it is easily obtainable in the field.

10Micron and ASA mounts track in both axis and have absolute encoders. This means that you can have a much larger polar alignment error and still get away with unguided imaging. The mounts need good models in order to deliver unguided.

ASA's software has the path tracking option as you mention. The same is doable with a 10Micron mount if you just choose to model along the path of the intended target. Easily done with my model making software (you can read about that on my site).

/per


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Hilmi
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Per Frejvall]
      #6094941 - 09/22/13 12:03 PM

Per,

I thought all software based on Linux has to be open source or is in violation of the license agreement. Anyway, that doesn't affect me in any meaningful way.

You are right about polar alignment, when I took those 40 minute exposures I had spent several hours tuning my polar alignment using PEMPro.

Guiding is not an issue for me since my camera already has an off axis guider built in, my aim is to get the images so I don't care if it is done with or without guiding. I am just interested in getting images in the longer focal lengths. Defined in my dictionary as starting from 1680 mm going upwards from there.


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petely
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Hilmi]
      #6095016 - 09/22/13 12:49 PM

I've been casually considering the same kind of problem. One point that may be important to you: the DDM mount control software seems to be the creation of a single individual. If that guy gets bored, gets a better offer or his situation changes, would the company be able to keep supporting the mount? Without the control software, the mount is just a pile of highly machined metal.

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GIR
super member


Reged: 01/02/10

Loc: Finland
Re: ASA DDM60 Pro vs. GM1000HPS new [Re: petely]
      #6095057 - 09/22/13 01:20 PM

Just have to comment on this

Yes ASA is using Dr. Keller as their main developer. However, if you'll check out what kind of a company ASA is, they should be able to hire a replacement for Mr. Keller if he gets hit by the truck.

And if you compare ASA to e.g. 10Micron who had problems to develop even proper ASCOM support without a help of a talented mount owner, not to even talk about other software development. I'd put my money on ASA


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Per Frejvall
sage


Reged: 09/28/12

Loc: Saltsjöbaden, Sweden
Re: ASA DDM60 Pro vs. GM1000HPS new [Re: petely]
      #6095062 - 09/22/13 01:24 PM

Hilmi,

If that is your requirement then both mounts will do. I prefer the 10Micron for a number of reasons. I do not like the total PC dependancy, I do not like the fact that if power is cut the thing is loose as a goose and can continue its slew until it hits the pier, and I do not like motor control to be delegated to an external computer.

As for the Linux thing, all things Linux do not have to be open. It is the base embedded Linux kernel code that is open, not the firmware riding on it.

Now, if you are aiming for the longer focal lengths I would suggest you look at mounts "one step up". In 10Micron terms that would be the GM2000HPS. It is a formidable mount!

/per

Edited by Per Frejvall (09/22/13 01:25 PM)


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orion69
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Reged: 05/09/10

Loc: Croatia
Re: ASA DDM60 Pro vs. GM1000HPS new [Re: petely]
      #6095064 - 09/22/13 01:25 PM

Hilmi, can we see this 40 min unguided image with G11?

Edited by orion69 (09/22/13 01:26 PM)


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Hilmi
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: orion69]
      #6095084 - 09/22/13 01:38 PM

Will dig it up. I have the 20 minutes posted on astrobin. My g11 is upgraded with ovision worm and has a +/- 3 arc seconds pe. But it just won't guide properly and keeps on giving RA jumps larger than the PE. I thought it was seeing at first but dec axis plot is perfect.

Anyway. I'll go to my computer and dig up those 40 minute subs


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Hilmi
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Hilmi]
      #6095156 - 09/22/13 02:19 PM

I wish to retract my statement about 40 minutes unguided as I found I was using an auto-guider upon reviewing my images. I apologize for any shock and indignation I might have caused with that mistaken statement.

But I did manage 40 minutes guided


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GIR
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Loc: Finland
Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Hilmi]
      #6095175 - 09/22/13 02:33 PM

Quote:

...I have the 20 minutes posted on astrobin...





Hilmi

Could you give a link to that 20min unguided exposure at the Astrobin. Could only find one 4 min unguided exposure.


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Hilmi
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: GIR]
      #6095187 - 09/22/13 02:50 PM

Please look at the above statement. I made that statement out something I recalled incorrectly and I have posted an apology for my false statement.

That still doesn't change the fact that I want to see results from longer focal lengths.

Anyway, here is the picture I was referring to, it was not in the public area, it was in the staging area.

http://astrob.in/37174/

I will find the 40 minute sub and post it anyway.

Edited by Hilmi (09/22/13 03:08 PM)


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GIR
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Hilmi]
      #6095226 - 09/22/13 03:23 PM

Hilmi

Hope you'll find a good mount for your longer focal length plans. It shouldn't be a problem because doing longer focal length with autoguiding is quite manageable with all high end mounts.
Maybe you'll also find out one day that taking 20 min unguided exposures with a 600 mm scope isn't so trivial you seem to think.


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Hilmi
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Hilmi]
      #6095231 - 09/22/13 03:28 PM

Found the 40 minute raw sub. It's a 16 meg file so I am posting a link to drop box. As I have mentioned earlier, it is auto-guided and I had made a mistake when I thought it was not guided.

https://www.dropbox.com/sh/j3jfcfmys14gzy0/pW2m5V8mj8


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Hilmi
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Hilmi]
      #6095240 - 09/22/13 03:34 PM

Thanks GIR. I do not intend to trivialize the achievement I mean to say that I want to see results in the focal lengths I am working at.

When I purchased the G11, I was told that it can do 2000mm imaging, but I actually didnt see any results and now I am not happy at all with it's guiding performance. So I can't be blamed for looking to see actual evidence of performance at the same focal lengths I am working at.

I saw an image from a DDM85 at 4500mm that was unguided and very impressive. but a DDM85 is not a DDM60. While the principles of operation are the same, I would still like to see feedback from users of the same mounts I am considering.

Same goes for GM1000HPS. Lots of feedback on the GM2000HPS, very little on the GM1000HPS.

I found lots of information about the Paramount MX and The Mach1GTO. That was so easy to dig up.


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frolinmod
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Reged: 08/06/10

Loc: Southern California
Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Hilmi]
      #6095579 - 09/22/13 07:00 PM

Quote:

I found lots of information about the Paramount MX and The Mach1GTO. That was so easy to dig up.



That should tell you something.


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orlyandico
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: frolinmod]
      #6095700 - 09/22/13 08:25 PM

Hilmi, if I were you I'd find some friend traveling to the US who can get you a used AP900GTO. Certainly it can't do the 20-minute unguided trick of the 10Micron and ASA mounts, but as frolinmod just implied... it's a bulletproof and no surprises solution. Since you indicate you'll be guiding anyway.

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shams42
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: orlyandico]
      #6096021 - 09/22/13 11:34 PM

I found myself in a similar quandry. I am fascinated by the 10Micron mount in particular and have read the instruction manual several times. It sounds amazing. Ultimately I ended up going with the Paramount MX due to all the information out there and the mature software integration. It also helps that the PMX can carry about twice the weight of the GM1000. I am hoping to try some unguided images via ProTrack and TPoint. The PMX arrives on Tuesday!

My Takahashi NJP has been an amazing mount for guided imaging and truthfully its only shortcoming is that it doesn't thrive in an automated environment.


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GIR
super member


Reged: 01/02/10

Loc: Finland
Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Hilmi]
      #6096149 - 09/23/13 01:30 AM

Quote:

...I saw an image from a DDM85 at 4500mm that was unguided and very impressive. but a DDM85 is not a DDM60. While the principles of operation are the same, I would still like to see feedback from users of the same mounts I am considering...





If you're seriously wanting to learn more about ASA mounts, you might want to check out some of the user experiences from their web site. It includes all kinds of set-ups. ASA forum is also a good place to ask what kind of results people are getting from their systems.

ASA


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Hilmi
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: GIR]
      #6096225 - 09/23/13 03:16 AM

Gir,

Thanks for the link. I have now found the sort of samples I was looking for. I found images done on a 10" LX200 unguided and they looked very nice.


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Per Frejvall
sage


Reged: 09/28/12

Loc: Saltsjöbaden, Sweden
Re: ASA DDM60 Pro vs. GM1000HPS new [Re: GIR]
      #6096264 - 09/23/13 05:27 AM

Quote:

Just have to comment on this

nd if you compare ASA to e.g. 10Micron who had problems to develop even proper ASCOM support without a help of a talented mount owner, not to even talk about other software development. I'd put my money on ASA




Well, they were late in releasing their ASCOM driver, that I can confirm. In the meantime I developed my own which is entirely mine and has nothing to do with 10Micron. Today both are available.

/per


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Hilmi
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Per Frejvall]
      #6096290 - 09/23/13 06:29 AM

I see there is some healthy rivalry between the mount owners.

Per,

Did you purchase your mount with the full kit including the tripod and carry cases? How good re these accessories? Do you feel they are good enough to be considered influential in the purchase decision?


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GIR
super member


Reged: 01/02/10

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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Per Frejvall]
      #6096315 - 09/23/13 07:29 AM

Quote:

Quote:

Just have to comment on this

nd if you compare ASA to e.g. 10Micron who had problems to develop even proper ASCOM support without a help of a talented mount owner, not to even talk about other software development. I'd put my money on ASA




Well, they were late in releasing their ASCOM driver, that I can confirm. In the meantime I developed my own which is entirely mine and has nothing to do with 10Micron. Today both are available.
/per




It was just a comment to the way ASA is doing their software development, and a reminder how important a good software package really is.

What comes to 10Micron and ASCOM support the situation is like Per described, however, I'm not sure the current situation is any better what comes to the future software development.

Let's take the "local pointing model" which ASA already has, and which is quite a useful and important tool when doing unguided imaging.
As Per said earlier...

" ASA's software has the path tracking option as you mention. The same is doable with a 10Micron mount if you just choose to model along the path of the intended target. Easily done with my model making software (you can read about that on my site)"

Another example is the "Model Maker" tool which as far as I know is developed by Per. A quote from his web site:

"Model maker will completely automate the modelling of the sky and let you sit back with a cup of coffee while a 25-star model is built for you to a very high degree of accuracy. This application is a must and has taken many hours and crazy ideas to complete. I have released it as donor-ware and appreciate any contribution you want to give, large, small or non-monetary"

ASA on the other hand has a very sophisticated modeling tool as a standard feature.


For me it looksi like 10Micron is still not very active in developing their software package, and users have to make their own applications.

These are all of course personal preferences but was one of the main reasons I dropped 10Micron out of my list when was looking for a new mount.


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orion69
scholastic sledgehammer


Reged: 05/09/10

Loc: Croatia
Re: ASA DDM60 Pro vs. GM1000HPS new [Re: GIR]
      #6096346 - 09/23/13 08:06 AM

I'm also considering these two mounts. But since I plan to purchase another fast and short refractor for wide imaging and install it on top of my present refractor I'm afraid that capacity from both mounts is too small. So I'm looking into PMX as a third option, I think that 40 kg would be enough.
I don't know if that would be an option for OP since PMX doesn't come with absolute encoders.


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Hilmi
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: orion69]
      #6096588 - 09/23/13 10:47 AM

I had originally considered the MX. I just wanted to consider options from Europe which for me will save me shipping cost if in the future I need technical support and have to send bits and bobs for repair.

I hqve had excellent response for support for my g11 but it costs a small fortune every time I have to send something back to the US for repair.


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tomcody
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: GIR]
      #6097267 - 09/23/13 06:36 PM

GIR,
Could you please tell me about how the mount works with the power off? does the RA and DEC axis just turn freely? and if that is true? does the scope ( when mounted) just swing to its balanced point ( kind of like realeasing the clutches on a gear driven mount) . How do you put the scope on the mount ? do you have to have the power on to prevent the mount from moving while you set the scope on the saddle?
thanks, Rex


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GIR
super member


Reged: 01/02/10

Loc: Finland
Re: ASA DDM60 Pro vs. GM1000HPS new [Re: tomcody]
      #6097789 - 09/24/13 01:32 AM

Good questions Rex...

Yes the scope can move freely when the power is off, however, it's perfectly balanced so it doesn't move into any specific position. It'll always stay exactly where you've stopped it. So it can be parked or stopped into any position.
First it felt a bit odd but now it's kind of neat because you can rotate the system around when doing initial balancing or whatever reason you'll need to rotate the scope.

When you turn the power on the whole system will become very stiff, but it's kind of "elastic stiffness" and you can feel the resistant growing when gently pushing the scope.

It's good to remember that the encoders send signals to the mount 100x per second so the mount is able to react even into wind gusts and stay on track.

I've made some experiments to see how the mount reacts to the external interferences. Knocking the pier(I have a steel-concrete combination) will cause 1-2 arc sec corrections and a bit more rough banging on the pier will cause larger correction signals but they are all made in a fraction of a second. So the mount really is able to smooth out wind gusts when tuned properly.

RA and DE axis have screws you can tighten when putting the scope on ...and of course you'll loosen them before operating the mount. Sometime I'll use them sometime I don't.


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Per Frejvall
sage


Reged: 09/28/12

Loc: Saltsjöbaden, Sweden
Re: ASA DDM60 Pro vs. GM1000HPS new [Re: tomcody]
      #6097801 - 09/24/13 01:51 AM Attachment (13 downloads)

About the advanced bolt-on software from ASA. I would agree that ASA are more active in developing the software that the user sees, but in the case of 10Micron the situation is not that different.

The mount does everything in firmware while the ASA mount is totally dead without a computer attached. Take the modeling:

  • The entire modeling of the sky is handled WITHIN the mount
  • The model holds 100 points max
  • You can save and recall models
  • It models polar error, ortho error and consistent flexure
  • The model is used for gotos and dual axis tracking - in-mount
  • The mount models atmospheric refraction - again in-mount

You get all those functions without having a computer attached. As for development, well, you get the modeling improved in software by means of firmware updates instead of Windows applications (and their inherent "stability").

When you model an ASA mount you use Autoslew, Sequence, MaximDL, Pinpoint and the GSC 1.1 catalogue.

When you model a 10Micron mount you can use the handpad or any external software that can send syncs. There is no off-mount processing required; the mount calculates the model on its own. Just add a sync point in any planetarium software and the model is improved.

My Model Maker is an external piece of software with a reasonably nice user interface and feature set. Baader Planetarium, the "business end" of 10Micron, features it on their we site, and my writing it and offering it to the community has probably made them back off on the production of their own software in favor of concentrating on the firmware in the mounts.

Model Maker lets you click a bunch of points, slews to them one by one, exposes, plate solves and syncs the mount to the solved coordinates. There is no magic modeling going on as that is handled by the mount. The next iteration of Model Maker (in the works) will speed up the process by storing all plate solves and sending them all to the mount in one batch (at the time of building or later from a file, firmware support for that was released today). The current version can iterate through the mount model and remove points with higher errors, all in order to reduce the complex model terms resulting expected RMS error. Again, calculations are done in-mount.

What I am trying to point out is that the principles of the ASA and the 10Micron mounts differ fundamentally. ASA is 100 percent computer dependent, 10Micron is not. ASA sports the cool direct drive concept but lacks automatic locks (power off and the goose is loose, start a slew and cut power and the slew just goes on until impact).

I would get an ASA mount today if it had the model and motor handling in the mount and some kind of locks that would engage upon power loss. Those are my ONLY objections to the ASA mounts, and to me they are show stoppers as I want to run my mounts unattended in remote locations, something I would not dare to do with an ASA today.

Now, there's a rather large two-center, right?

/per


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Per Frejvall
sage


Reged: 09/28/12

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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Hilmi]
      #6097813 - 09/24/13 02:16 AM

Quote:

I see there is some healthy rivalry between the mount owners.

Per,

Did you purchase your mount with the full kit including the tripod and carry cases? How good re these accessories? Do you feel they are good enough to be considered influential in the purchase decision?




I got my GM2000HPS with the Centaur tripod (what a product!) and the carrying cases. Since I am now entirely going for remote stuff that would not have been my choice had I known. The GM1000 fits the tripod after drilling and tapering of three holes, and I got the GM1000 "naked" with two counter-weights.

/per


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GIR
super member


Reged: 01/02/10

Loc: Finland
Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Per Frejvall]
      #6097815 - 09/24/13 02:20 AM

Quote:

What I am trying to point out is that the principles of the ASA and the 10Micron mounts differ fundamentally. ASA is 100 percent computer dependent, 10Micron is not. ASA sports the cool direct drive concept but lacks automatic locks (power off and the goose is loose, start a slew and cut power and the slew just goes on until impact).

I would get an ASA mount today if it had the model and motor handling in the mount and some kind of locks that would engage upon power loss. Those are my ONLY objections to the ASA mounts, and to me they are show stoppers as I want to run my mounts unattended in remote locations, something I would not dare to do with an ASA today.





Per, It's kind of funny how fiercely you defend 10Micron and pick on ASA. First it was the encoders and now the "loose goose" thing. All I can say that ASA mounts are used a lot also remotely all over the world, and I've never heard or experienced myself anything even close what you're implying.

I have no interest in promoting ASA, just telling my experiences when someone asks. There is a lot of information available on ASA mounts, including user experiences. So anybody can find out themselves what ASA is all about and doesn't have to make decissions based on comments made by people who've never even used the mount. Anyway, I'm sure all high end mounts are able to do their job very well…


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Per Frejvall
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: GIR]
      #6097836 - 09/24/13 03:26 AM

Gir,

Please don't take this as "fierce defence" or "picking". I guess I'm just defending my own choices. The DDM60 was on my short list and I decided against it. I now have input from a bunch of people running it and some are very happy, while other (50/50) are not, a fact that makes me wonder a bit. Obviously, you are on the good end

Also, I believe hey now ship the 60 with true encoders - a fact that merits them. From a pure opinion standpoint, I don't think anyone could convince me about the soundness of having motor control via USB, that's just what I am. I design electronics and software a lot and am not very keen on being USB dependent.

So, again, don't interpret my rants as fierce, they really are not, just another voice in a never ending debate.

/per


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GIR
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Per Frejvall]
      #6097878 - 09/24/13 05:43 AM

Per,

As far as I know DDM60 has been shipped with the same encoders than other ASA mounts for sometime already. What comes to unhappy ASA mount owners you seem to know them all because the complaints I've heard are quite rare and not on issues you've been talking about.
But let's end this pointless discussion here and let people buy what ever mount they feel suits them best


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Nodinute
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: GIR]
      #6097892 - 09/24/13 06:32 AM

I've seen this thread on the equipment forum.
May be this Direct Drive Mount could be a solid challenger..
http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Number/6044045/page...


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Per Frejvall
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Nodinute]
      #6097915 - 09/24/13 07:32 AM

Yes, that is a very nice looking mount! I'd be very interested in more details about it. Must Google...

Gir, agreed!

/p


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famax
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Per Frejvall]
      #6103681 - 09/27/13 09:01 AM

Hi there,i have the gm 1000 full package.
it is really nice and well made. No problem with the quality.
Unguided images supposes good & quick moddeling if you' re in the field which i'm.

The plus of the 10µ is it feels simple to use (compared to what i saw from ASA, which look very complex...)

The minus is the lack of modelling devellopement which should not has been done by an external as Per.

by the way 10µ is very reactive in the update of firmware and drivers

Edited by famax (09/27/13 09:03 AM)


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Hilmi
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: famax]
      #6103812 - 09/27/13 10:07 AM

Famax,

How are the accessories provided such as the tripod and the carry cases. I understand the carry case uses the same foam the mount came with. Is the foam good enough to last a long time?


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Tonk
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Hilmi]
      #6107678 - 09/29/13 02:53 PM

I'm a proud owner of a new 10Micron GM1000HPS mount. I originally planned on a Paramount MX

On talking to the vendor (Ian King) about my specific needs - lengthy unguided tracking and a self contained system with no external computer required - especially as I go mobile to remote elevated sites, he recommended the 10Micron.

I've been running it 2 months now. I can consistently get polar alignment to within a bounds of 25 to 15 arc seconds error using just the built in firmware. Firmware upgrades are easy to install when needed.

I am able to shoot unguided reliably for 10 minutes at FL 600mm - in fact I've only dropped 2 frames so far due to tracking errors.

I use the mount unattended most of the time and its 100% reliable so far - so far that's 12 sessions - so its still new stuff so long term reliability is still to be tested.

I've just posted a separate thread on the consequences of a pier crash - the results was NO loss of pointing accuracy even though the mount was driving the camera against the pier plate for 30 seconds before I got my wits back into gear and found the stop button (the original error is mine - I still need to set slew limits).

So all in all the mount services my needs 100% and exceeds my expectations. I guess the only issue might be the load limits but right now my scopes are well within bounds. The mobile and self sufficiency ticks are the prime reasons I got this mount.


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GIR
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Tonk]
      #6108554 - 09/30/13 01:17 AM

Quote:

I've just posted a separate thread on the consequences of a pier crash - the results was NO loss of pointing accuracy even though the mount was driving the camera against the pier plate for 30 seconds before I got my wits back into gear and found the stop button (the original error is mine - I still need to set slew limits).






Sorry to hear about your pier crash. I've been pretty close myself couple of times, and now make sure that the slew limits are always in place.

In ASA mounts the Autoslew program will register a rapid rise in motor current if the mount hits the pier and switch off the motors. Of course setting the limits correctly will always a better option


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tomcody
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: GIR]
      #6108620 - 09/30/13 02:53 AM

One Big difference between these mounts is that the micron is old standard worm and gear technology, with all the wear , damage ( to the gear teeth) and adjustments that a precession gear drive needs. The ASA has no parts to adjust or wear except the main shaft bearings. Big difference in long term maintenance! As for where the computer is housed? who cares? both need one, does it really matter where the box is located?
Given a choice, I would take the direct drive system any day just from a maintenance standpoint.
The long time argument against direct drive was high power use in the field, as ASA seems to have solved that issue, there basicly is no downside to direct drive.
Rex


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Beerologist
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: tomcody]
      #6108652 - 09/30/13 03:40 AM

"The long time argument against direct drive was high power use in the field, as ASA seems to have solved that issue, there basicly is no downside to direct drive."

As I recall that false argument about power consumption was made repeatedly by a fan of another mount mfgr (one that doesn't use direct drive tech) even though it was explained to him several times by different people that he was knowingly talking guff to try to make the direct drive mounts look bad.

Far as I know the ASA mounts have never had a high power consumption problem. They seem pretty darn slick to me and I'd be happy to own one.


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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Beerologist]
      #6108657 - 09/30/13 03:49 AM

Guys, I appreciate all the feedback, but I think this discussion would have more value if the users talked about the mount they had without making assumptions about mounts they don't have. For example assuming that a certain mount would wear out pre-maturely. Plenty of high precision worm gear driven mounts are going strong after more than 10 years of use and considering worms are replaceable parts, I don't feel 10 years is so bad.

I really just wanted the personal experiences with the individual mounts. Any frustrations faced during the learning phase, ease of setup in the field. Any failures failed. Any downsides you see to the mount you have (admit it, everything has a down side, nothing is perfect). I would rather hear about the downsides from people who own the equipment than from people for make assumptions about the equipment.

Think of it this way, it's not a competition to see which mount is better and who was the smarter person for choosing this one over that. This discussion is supposed to be reference material for people like me to make up their minds about purchase decisions based on objective evidence and subjective preferences as seen by the owners of these mounts. Then the buyer can see how the subjective and objective opinions fit in with their own criteria and make a purchasing decision based on some useful information. If we keep on trying to prove which mount is better we might not get anywhere. Such a dispute could take more than 10 years to resolve.


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famax
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Hilmi]
      #6108732 - 09/30/13 06:48 AM

Hello , just taking a little time to give more feedback about
the gm1000 full package.

The full package is now delivered with pelican cases type cases.. very solid. foam is grey and look durable;

The wood pier is from geoptik, hercule series.
I find mine a little to high , but one can ask for the short version of this pier.
Nothing to say about, it does well its job.

One downside of the 10µ is it is heavy : 19 kg and monoblock.
so taking it in the fields require a good back.

Something anoying is that you have to put the mount near polaris below 7° in azimuth.
A good compass allows it, but i would prefer a laser like solution for pre-positionning the mount.

The mount itself do not have major default, the tracking is very smooth, on of the best in its class.
and Once used two or three times , it is very easy to use.


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GIR
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Hilmi]
      #6108773 - 09/30/13 07:44 AM

Quote:

Guys, I appreciate all the feedback, but I think this discussion would have more value if the users talked about the mount they had without making assumptions about mounts they don't have. For example assuming that a certain mount would wear out pre-maturely. Plenty of high precision worm gear driven mounts are going strong after more than 10 years of use and considering worms are replaceable parts, I don't feel 10 years is so bad.

I really just wanted the personal experiences with the individual mounts. Any frustrations faced during the learning phase, ease of setup in the field. Any failures failed. Any downsides you see to the mount you have (admit it, everything has a down side, nothing is perfect). I would rather hear about the downsides from people who own the equipment than from people for make assumptions about the equipment.






Hilmi

I think you should listen to all kinds of arguments and decide yourself what is relevant and what is not. The fact is that both ASA and 10Micron are pretty newcomers and you'll have hard time to get comments of their longtime use from actual owners.

The other fact is that ASA direct drive technology is something that we haven't seen before or at least have heard very little about it. I can only tell about my own experience and don't really care if someone else is buying an ASA mount or not. If looking at the comments about ASA mounts, most of it is irrelevant, concentrating to some odd detail or simply doesn't make any sense. Besides most of the critical comments seem to come from people who have never even used the mount themselves, pure rumors and gossip. That is the main reason highlighting mainly downsides in a forum like this is quite useless.


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CounterWeight
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: GIR]
      #6108794 - 09/30/13 08:02 AM

Just wanting to chime in - great thread and initial OP question! (Thanks for asking it Hilmi) I am going to upgrade to something from my Mach1 pretty soon and find all this very interesting. Not long ago was near impossible here to discuss this / these without a huge noise level - this thread informative and a breath of fresh air. Again my thanks to those participating.

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Tonk
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: CounterWeight]
      #6108850 - 09/30/13 08:54 AM

Quote:

Plenty of high precision worm gear driven mounts are going strong after more than 10 years of use and considering worms are replaceable parts, I don't feel 10 years is so bad.





You might like to know that my 10Micron documentation says that no servicing of the mount will be required for up to 20 years though you can opt for a 10 year service if you wish. There is nothing for the user to adjust and the gearing is all sealed inside with "warranty void if broken" stickers.

Now I have only been running my mount 2 months so no way can I validate that the worms have such a lifetime. However you have to ask why Comec have such faith in their "old fashioned" worm gears if worm drives are truly that inferior to direct drive.

The only thing I can validate is the incredible pointing accuracy and highly successful long period unguided imaging I'm getting. Having the encoders on the shaft side of the worms means that the absolute shaft position can be monitored and stuff like backlash and PE corrected out by the firmware driven mount controller. This just leaves residuals in the corrected drive controller (very low), PA error and atmospheric refraction as your main enemies to unguided tracking.

One thing I have noticed is due to the absolute (shaft) encoder design, tracking has to accurately model atmospheric refraction for low altitude targets. Hence you need to input your height above sea level and the current atmospheric pressure to successfully track unguided for > 10 minutes when the target is below 25 degrees. (Consequently it might be nice if an electronic barometer could be attached - I need to ask the vendor if such optin exists). However at my dark sky site I'm in a clearing where the lower 30 degrees of sky are masked by trees - so it is not an major issue for me, though I have noticed a small tracking accuracy problem if I pick out an eastern target that just clearing the tree tops. As it rises the tracking gets better as refraction effects drop off.

I'm still learning how to use this mount, but from the go its been a blinder. Losmandy Gemini users would easily adapt to this mount and its controller as the pointing model building and PA correction procedures are very similar


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Tonk
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Tonk]
      #6108868 - 09/30/13 09:04 AM

Quote:

Sorry to hear about your pier crash.




The point I was making in my other thread about the pier crash was no damage was done and pointing accuracy was maintained 100% even when the clutches slip. So the 10Micron design has that covered. It too does a current surge measurement and instantly backs off driving hard - it lets the internal clutches slip. I.e I had nothing to worry about!


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GIR
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Tonk]
      #6108923 - 09/30/13 09:31 AM

Quote:



However you have to ask why Comec have such faith in their "old fashioned" worm gears if worm drives are truly that inferior to direct drive.






Tonk

Glad to hear that you've been happy with your mount purchase. And I'm sure 10Micron is an excellent mount. However, comments like above just don't add any value when trying to compare different mounts. I doubt that people start calling to Comec (what ever that is) to ask why they're using worm gears in their products
And I'm sure the world is full of worm gear products but only few direct drives, especially implemented in the ASA way.


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tomcody
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Beerologist]
      #6108987 - 09/30/13 10:10 AM

Quote:

"The long time argument against direct drive was high power use in the field, as ASA seems to have solved that issue, there basicly is no downside to direct drive."

As I recall that false argument about power consumption was made repeatedly by a fan of another mount mfgr (one that doesn't use direct drive tech) even though it was explained to him several times by different people that he was knowingly talking guff to try to make the direct drive mounts look bad.

Far as I know the ASA mounts have never had a high power consumption problem. They seem pretty darn slick to me and I'd be happy to own one.




I was referring to the fact that direct drive started out in professional observatories and was considered not usable in the field due to the high power consumption of systems at that time, now that ASA and other makers have designed low power consumption drives, there is no downside. You are just not looking back far enough to follow my statement.

Also as far as my statements about maintenance on gear /worm drives, it is a fact that they contain many precision machined and assembled parts and those parts are subject to wear and damage (just drop a gear/worm mount head in its crate with the clutches locked {which they should never be shipped locked as it transmits the shock of handling to the worm/gear matting point, but it does happen, both the shipping locked and the dropping} and you can damage a gear tooth and cause a periodic error at that tooth, or crash a mount into the pier and if the clutches or motor overload sensors do not work? do the same damage.
As there are no parts like that in a direct drive mount, that can't happen.

I am not trying to say which type of mount is better, just that the direct drive mounts change the game the same way a solid state wrist watch does compared to a old fashioned clock drive one.
Rex


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Tonk
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: tomcody]
      #6109021 - 09/30/13 10:34 AM

Quote:

However, comments like above just don't add any value when trying to compare different mounts.




Should I remove it then??

All I've been telling you is exactly how my GM1000HPS performs for me so others can get some idea from a user of the mount. I just found it odd that mounts using worms were being down played as possibly inferior to direct drive when evidence from actually using the GM1000HPS says this is actually a top class mount.

How many worm drive mounts track accurately for 10 to 20 minutes so that you can go unguided that long??

The thing is how does this particular solution - (worm drive + absolute encoders) really compare to a direct drive solution?

As I have no experience of the latter I can't actually comment - all I can say is the GM100HPS vastly exceeded my expectations and the worm drive + absolute encoder combination really works well.

Quote:

And I'm sure the world is full of worm gear products but only few direct drives, especially implemented in the ASA way.




So you have totally missed the point about the use of absolute encoders - its not just any old worm drive. Absolute encoders means that the method of driving isn't that important as long as the feedback loop can correct drive errors fast enough by measuring the absolute position of the shafts and correcting the position in real time. The shaft position encoders have a resolution to better than 1 arc second (will have to check manual for actual value)

So there are equally very few worm + absolute encoder solutions as there are "ASA way" direct drives

Would you like to start again?


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GIR
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Tonk]
      #6109057 - 09/30/13 11:03 AM

Quote:


So you have totally missed the point about the use of absolute encoders - its not just any old worm drive. Absolute encoders means that the method of driving isn't that important as long as the feedback loop can correct drive errors fast enough by measuring the absolute position of the shafts and correcting the position in real time. The shaft position encoders have a resolution to better than 1 arc second (will have to check manual for actual value)

So there are equally very few worm + absolute encoder solutions as there are "ASA way" direct drives

Would you like to start again?




So 10Micron isn't just a worm drive but a worm drive with absolute encoders. I think I got it now


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tomcody
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Tonk]
      #6109068 - 09/30/13 11:14 AM

Quote:

So you have totally missed the point about the use of absolute encoders - its not just any old worm drive. Absolute encoders means that the method of driving isn't that important as long as the feedback loop can correct drive errors fast enough by measuring the absolute position of the shafts and correcting the position in real time. The shaft position encoders have a resolution to better than 1 arc second (will have to check manual for actual value)




One thing to remember, with absolute encoders, yes they can over come errors in the PE due to gear irregularities but they can not overcome mechanical looseness in the drive train. In the industry there is a truth that the position error you are trying to maintain, must be greater than the mechanical play in the drive train. (i.e. in your example if you are trying to hold 1 arc second of position, but you have 3 arc seconds of mechanical looseness in the drive train? then your system will hunt back and forth trying to hold a position. In 30+years of designing installing, and servicing servo drive CNC and robotic systems, whenever a machine would not hold position, (even with absolute encoders) it was almost always a mechanical looseness problem.
(which is why I say that a direct drive system has less fail points than a gear drive system).
And while I am still not saying which system is better, I am just pointing out the differences.

But if I were in a remote land and service was thousands of miles away, I would rather ship back a servo drive board or drive package , ( the most likely point of failure on a direct drive system) for repair rather than the entire mount head.

Rex

Edited by tomcody (09/30/13 09:03 PM)


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Tonk
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: tomcody]
      #6109393 - 09/30/13 02:49 PM

Quote:

Comec (what ever that is)




Ah! Comec Technology is the Italian company that make 10Micron mounts - hope that helps


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famax
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: tomcody]
      #6109407 - 09/30/13 02:55 PM

hi all,

A thing to consider , and maybe GIR could tell more about , is that the direct drive needs careful PID adjusment which is not an easytask, but has to be done only once, given the setup is not modified.
To say , balance has to be near perfect with DD technology (as i remember, maybe it evolved since first batch of ASA's mounts...)

By the way, here are some images about the 10µ











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Tonk
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Tonk]
      #6109425 - 09/30/13 03:07 PM

Quote:

One thing to remember, with absolute encoders, yes they can over come errors in the PE due to gear irregularities but they can not overcome mechanical looseness in the drive train.




Good point. My mount doesn't seem to have this problem (yet - crossed fingers). I can hear the motor whine and its tone changes on direction so you can hear when hunting is happening - does happen but its its is very infrequent and lasts less than a fraction of a second. The first time I heard the "hunting cry" it did startle me

One interesting thing caught my attention the first time I was setting up a pointing model. Switching to a star target on the western side of sky having done the 3-star initial alignment on the east was very accurate - within my astrometric eye piece bullseye.

I've been used to a Losmandy/Gemini system for 10 years and the first time switch to western side target when setting up this mount is usuatlly way off (a degree is normal) and the mount has to be repointed and the modeler in the Gemini controller updated to add a term for the east/west flip positioning error.

The GM1000HPS doesn't suffer this - so I assume this is a feature/benefit of using absolute encoders. Whatever the reason its nice not to have this pointing error term to deal with!


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Tonk
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Tonk]
      #6109439 - 09/30/13 03:15 PM

Two other useful features that come with the GM1000HPS

1) It can measure balance (by monitoring motor current) and guides you to the correct balance point. Does both RA and DEC balance.

2) You can elect to have RA tracking or RA + DEC tracking. The latter is useful for dealing with correcting out residual PA errors but obviously if your imaging time is too long field rotation will creep in. This is taking advantage of the absolute encoders and the measured PA error from the pointing model.


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Tonk
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Tonk]
      #6109462 - 09/30/13 03:26 PM

Quote:

Hello , just taking a little time to give more feedback about
the gm1000 full package.

The full package is now delivered with pelican cases type cases.. very solid. foam is grey and look durable;






Bugger! Mine came in a (very sturdy) cardboard box.

I've just checked - the pelican case option is an extra cost option. You can also get a zippered "soft case" option that reuses the solid padding block that was inside the cardboard box.


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GIR
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: famax]
      #6109493 - 09/30/13 03:42 PM

Quote:



A thing to consider , and maybe GIR could tell more about , is that the direct drive needs careful PID adjusment which is not an easytask, but has to be done only once, given the setup is not modified.
To say , balance has to be near perfect with DD technology (as i remember, maybe it evolved since first batch of ASA's mounts...)






famax

Yes, as has been said already before ASA mounts need a careful PID adjustment, which can be done most of the time with Autoslew automated process and sometime there is a need for some additional manual adjustment. However, even the manual tuning is done with the help of real time graphics, and really isn't that difficult.

The other critical thing is balancing the mount and again that can be done with the help of Autoslew. All this has to be done only once (if the system hasn't been changed) and isn't really any rocket science even though will require reading the manual.

Let me add one more comment and I'm done answering these kind of questions...
Most of the complains (even from ASA mount users) seem to origin from the fact that people are not taking couple of hours to learn how to use the direct drive mount properly. And the critique here is based mostly on rumors and hearsay from people who have never even seen an ASA mount.

So what was the point for your comment ?
Learning the basics of Photoshop is far more demanding than learning to tune ASA mounts. If that is too difficult then one should to reconsider if astrophotography is a right kind of hobby for him/her.


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Tonk
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: GIR]
      #6109707 - 09/30/13 05:46 PM

Quote:

The shaft position encoders have a resolution to better than 1 arc second (will have to check manual for actual value)




Just looked it up - they state encoder resolution is 0.13 arc seconds giving in practice a RMS of 0.5 arc seconds tracking accuracy

This following quote from Ian King Imaging about the 10Micron mount is a claim I haven't yet verified for myself ...

Quote:

Tests with 3600 second long unguided exposures have show tracking accuracy within +/- 0.5 arc seconds.




However I can confirm that I had a test star remaining on the cross hairs of an astrometric 12mm eyepeice for 20 minutes. I stopped here because I was testing for planned 10 minute exposures. Scope FL was 600mm.


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famax
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: GIR]
      #6109720 - 09/30/13 05:54 PM

No particular point in my comment Gir, just wanted to clarify (or have someone to...) this point.
To say, and by reading the asa's forum , the DD seems very nice , but far more complexe than old school worm+encoders...
This is my feeling, and that led me to choose the 10µ.
By the way , and for other consideration , would a ddm 60 fit with in the field astrophoto ?

I think i would be great to read a real Pro/cons about the ddm60.


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GIR
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: famax]
      #6110396 - 10/01/13 12:10 AM

famax, the complexity comes from not bothering to read the manual
Usually things feel complicated when you don't know how to do them, once you do they're quite simple.
What comes to ASA, it really isn't that complicated just a bit different, and in return you'll get an astonishing mount.
I've already given my view on the the field use issue on another thread.


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Hilmi
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: GIR]
      #6110465 - 10/01/13 01:13 AM

I also find it a bit of a put off that the ddm60 doesn't have a matching tripod being sold by the manufacturer.

This tells me it was designed with permanent installation in mind


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GIR
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Tonk]
      #6110466 - 10/01/13 01:14 AM

Quote:


Just looked it up - they state encoder resolution is 0.13 arc seconds giving in practice a RMS of 0.5 arc seconds tracking accuracy






Not trying to downplay 10Micron but just to compare...
ASA Renishaw encoders provide a 0.01-0.02 arc sec resolution, and can track around 0.2 - 0.4 arc sec depending on your setup.
With my quite stable system tracking seems to stay around 0.1 - 0.2 arc sec.

And a question... doesn't +/- 0.5 arc sec tracking mean 1 arc sec in reality ?


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Tonk
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: GIR]
      #6110556 - 10/01/13 04:02 AM

Quote:

Not trying to downplay 10Micron but just to compare...




I thought this excercise was to give experiences and (verified) facts. Its not about downplaying.

Ah at least we are learning what the ASA can do in a little more detail

Quote:

The thing is how does this particular solution - (worm drive + absolute encoders) really compare to a direct drive solution?




So for the numbers collected/quoted its approaching an order of magnitude in favour of the ASA direct drive. So it sound like these two mounts are actually in different classes.


For me the price (~Ł6,000) and performance has hit the sweet spot. The GM1000HPS tracks unguided longer that I can use due to sky conditions and my prefered targets (comets) - it tracks with an accuracy better than the resolution of my imaging system - I shoot with a pixel width of 2 arc seconds)

For me buying a mount that tracks at 0.1" accuracy is a pointless waste of money and this might might be so for others. I shoot comets and long focal length work disfavours these targets.

Finally the mount really is mobile and extremely quick to set up anywhere. On my first test runs I did PA from scratch 6 times and was typically down to a mean of 15 arc second error in 15 minutes of model building and PA correction (thats 2 or 3 iterations on 12-15 stars).

The mount is increadibly easy to set up in a short time - very much like the Losmandy/Gemini systems. However the GM1000HPS is also approaching an order of mag better at unguided tracking than my Losmandy GM-8

I 'd like to say something about the vendor who sold me the mount - I came to him with the desire to buy a Paramount MX but once I explained to him what I shoot, and with what scope, where I shoot and a desire to "keep it simple" and set up quick (no guiding gear or extraneous equipment) I was pointed at the GM1000HPS. I'd never heard of the mount at this point - so on trust and 2 hours of playing with the mount - I went with his recommendation and I certainly don't regret it. Good man is Ian King! (and with the money saved I got an AstroTrac and other goodies )


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orion69
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Tonk]
      #6110568 - 10/01/13 04:26 AM

If I understood correctly ASA DDM60 or DDM85 is able to do 30min unguided imaging with my FL (<= 1000mm) and GM1000HPS or GM2000HPS can't (I believe it says so in manual).
For me that could be deciding point. If I'm buying expensive mount (for observatory), unguided shooting is very nice.
GIR, how much error can I expect unguided 30min with 1000mm refractor? Is there someone that have similar setup?


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orlyandico
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: orion69]
      #6110575 - 10/01/13 04:37 AM

I "heard" that ASA has moved from the Renishaw optical to the Renishaw / RLS magnetic encoders. Since the RLS encoders are 1um resolution with 2000-fold interpolation, I can't see how they can manage 0.01 arc-seconds.

I do know that the Renishaw Resolute ETR used in the AP 1100/1600 are capable of about 0.01 arc-seconds (sub-divisional error). But these are optical, and magnetic encoders are less accurate.

But then again that's just what I "heard." Take with multiple chunks of salt.


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GIR
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: orion69]
      #6110599 - 10/01/13 05:30 AM

Knez

You might want to ask that question from the ASA forum, and get more detailed answer. All I can tell that ASA mounts do perform very accurately when tuned and balanced properly.
The closer you'll get to the maximum (weight) limits the more careful you'll have be with the tuning and balancing.

I'm using a two scopes (600 mm and 300 mm FL ) and should be able to take as long exposures I want. However, haven't taken more than 20min subs (NB) so far because prefer to have at least 10 subs for each channel. Even with that the overall exposure time is 10 hours. Besides I've been shooting rather bright targets so far.

I will test longer subs sometime during the winter with the 600 mm (e.g. 60 minutes) just to see what happens but it's not really an important issue for me. The thing I've enjoyed the most (besides complete silence and unbelievable accuracy) is the ability to do unguided imaging. Guiding is not complicated but once you've gotten used to taking unguided pictures, it would be very difficult to go back for using guider scopes.


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orlyandico
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: GIR]
      #6110601 - 10/01/13 05:42 AM

Actually unguided imaging is not the exclusive preserve of direct-drive or encoder-equipped mounts.

I can do 600mm unguided subs for 10 and even 20 minutes with my ancient gear-driven encoderless mount. This is assuming the target is high enough above the horizon that atmospheric refraction isn't a factor (I don't have APCC Pro).

Basically above 45 degrees altitude I can do 10 minutes all the time at 600mm focal length (2.68"/pixel) and 20 minutes most of the time (say 50% keeper rate).

When altitude drops below 30 degrees I start getting exposures trailed in RA even on the 10-minute subs.


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orion69
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: orlyandico]
      #6110608 - 10/01/13 05:53 AM

Quote:

Actually unguided imaging is not the exclusive preserve of direct-drive or encoder-equipped mounts.

I can do 600mm unguided subs for 10 and even 20 minutes with my ancient gear-driven encoderless mount. This is assuming the target is high enough above the horizon that atmospheric refraction isn't a factor (I don't have APCC Pro).

Basically above 45 degrees altitude I can do 10 minutes all the time at 600mm focal length (2.68"/pixel) and 20 minutes most of the time (say 50% keeper rate).

When altitude drops below 30 degrees I start getting exposures trailed in RA even on the 10-minute subs.




I need 30 min, and that must be routinely and very precise.
Throwing subs is not an option. If you have to throw subs that means mount is not capable for the task.


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famax
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: orion69]
      #6110609 - 10/01/13 06:00 AM

Quote:

If I understood correctly ASA DDM60 or DDM85 is able to do 30min unguided imaging with my FL (<= 1000mm) and GM1000HPS or GM2000HPS can't (I believe it says so in manual).
For me that could be deciding point. If I'm buying expensive mount (for observatory), unguided shooting is very nice.
GIR, how much error can I expect unguided 30min with 1000mm refractor? Is there someone that have similar setup?




No, gm1000 and 2000hps can do very long unguided exp.
According to Per.

Some numbers here :

see :

http://www.astronamis.net/t2561-1-essai-10-microns-hps1000#32609
and
http://www.astrosurf.com/heidemann/Test%20GM1000HPS.pdf


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GIR
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: orlyandico]
      #6110610 - 10/01/13 06:00 AM

Quote:

Actually unguided imaging is not the exclusive preserve of direct-drive or encoder-equipped mounts.

I can do 600mm unguided subs for 10 and even 20 minutes with my ancient gear-driven encoderless mount. This is assuming the target is high enough above the horizon that atmospheric refraction isn't a factor (I don't have APCC Pro).

Basically above 45 degrees altitude I can do 10 minutes all the time at 600mm focal length (2.68"/pixel) and 20 minutes most of the time (say 50% keeper rate).

When altitude drops below 30 degrees I start getting exposures trailed in RA even on the 10-minute subs.




I'm sure you can after having perfect polar alligment and tuning everything well. But that's not the issue here. As far as I know ASA mounts are cabable of taking unguided images with far longer FLs than 600mm. It's just the way I'm using the mount.

I've tried taking unguided images with my Losmandy G11 and failed miserably. Maybe someone is able to do that but I wasn't. Now all I have to do... after Autoslew/Sequence polar allignment, and making completely automated pointing model and if being picky add "local" pointing model on top of that...is to "point and shoot". It doesn't matter if I'm taking 1 sub or shooting several hours. The only thing I have to think about is the Meridian flip if using the local pointing model. And as far as I know the next Sequence version will automate even that. It's so freaking easy ...and that's what I'm paying for.


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famax
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: GIR]
      #6110623 - 10/01/13 06:19 AM

What i find nice with the asa's is that there's a lot of thing to play with, and a lot of feeback from the system itself, giving good advice if you have flex in your system for exemple.
One could find it a bit complex , but i prefer this approach than the one of 10µ which is not very generous about the things hidden behind the model.

In fact, i would prefer a ddm for a static use , and a 10µm for in the field ops.


some more unguided tests :

http://stargazerslounge.com/topic/174111-best-mount-for-imaging-5k-6k-budget/...

Edited by famax (10/01/13 06:48 AM)


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jjongmans
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: famax]
      #6110693 - 10/01/13 07:46 AM

I'm using a DDM60.
I also did some unguided tests: link
My website: link


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Tonk
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: jjongmans]
      #6110715 - 10/01/13 08:17 AM

Quote:

gm1000 and 2000hps can do very long unguided exp.





Yes - absolutely. I've seen Per's results. I've tested myself to 20 mins (once @ FL 600mm) and IK Imaging claim 1 hour unguided (but don't say at what FL).

Collecting reports - this GM1000HPS review ...

Quote:

http://www.astrosurf.com/heidemann/Test%20GM1000HPS.pdf




... (Using Google translate) reveals that the review authors had perfect round stars after 10 minutes unguided at FL 2800mm

Then this GM1000HPS review/test ...

Quote:

http://www.astronamis.net/t2561-1-essai-10-microns-hps1000#32609




... has the author getting round stars at 25 minutes unguided @ FL 1080mm but at 40 minutes the stars are clearly oval.

For the ASA ...

Quote:

http://stargazerslounge.com/topic/170735-mission-accomplished-20-minuted-unguided-with-asa-ddm60/




... we have 20 minutes unguided @ FL 1383mm





Quote:

In fact, i would prefer a ddm for a static use , and a 10µm for in the field ops.




I would agree with this approach - oh if I could afford 2 mounts !


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Starhawk
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Tonk]
      #6110954 - 10/01/13 10:45 AM

Well, I have started off on a 10 Micron GM1000HPS test drive. So far I have just had it out one evening and started imaging with a C11 at 2800mm f/10 and experimenting with the Starizona f/7.5 reducer/flattener.

I haven't even pulled the images off the camera card yet- I promise to put centers and corners here when I do. Here are some first impressions- it's still in free form stream of consciousness in my mind. I'll have a much more organized impression of the mount when I get more time on it.

So far, the main observations I have are the mount is very complete in its standalone mode. The control box is about the size of the box for 7x35mm binoculars, so it is quite a bit larger than the CP 3 on a Mach 1. The plugs are all pointed up on the top. There isn't a hard mount bracket with the one I am using. Just one cable goes to the mount, and it goes between non-moving components. The mount powers on by pressing a power switch which looks like a mini rocker, but is actually a momentary switch. The mount boots and displays the startup status on the hand control as it goes through its checkout, which ends with an attempt to poll a GPS device.

The hand controller is also larger than the one on the Mach 1 GTO, and has true backlighting for the keys so it has very good legibility I. The dark.

The axes are very different from a Mach 1 GTO since they are free-turning when the clutches are released. So, balancing feels more like a CGEM in both axes. The dual vixen/Losmandy dovetail clamp was white secure though the first time I dropped the c11 into it in the dark, a leg went in the vixen slot and it wasn't obvious in the dusk, so pay attention before letting go.

The counterweights are very nice stainless steel cylinders with bronze clamping pins, but no bronze bushings like AP weights. The weight shaft is very close in size to the one on a Mach 1 GTO, but just large enough so 10Micron weights will go on a Mach 1 GTO, but Mach 1 weights will NOT go on the GM1000HPS. The shafts have radically different threads, so the mount can't be easily adapted that way, either.

The drive is something very new to me. It moves with power and authority with very little noise. 15 degrees/ second is really quick. I just did a 2 star align and then went on to a polar alignment. It was surprisingly easy, and from initial indications, extremely accurate. With more time I will try out making a true pointing model.

The drive constantly makes a soft sound like rubbing on something like a rubber surface from the high speed updates to the drive. In the eyepiece, the image is stationary. I took a series of 25 second exposures over 6 minutes at the focal lengths mentioned above. I'm thinking of stacking them without aligning to get some indication of the mount movement accuracy.

The wood 10Micron tripod is quite stout, and I was able to leave my hand on the C11 focus knob while focusing without jitter. I'll have to try that on the Mach1 GTO/ eagle pier combination to see what happens.

That's about all I have at the moment- I'll post back when I get my pix put together.

-Rich

Edited by Starhawk (10/02/13 10:06 AM)


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Per Frejvall
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Starhawk]
      #6111330 - 10/01/13 02:15 PM

Starhawk!

You are welcome to use my pointing/tracking model maker to speed things up. Available on my site.

I have one question regarding ASA. Does it need homing and does it home 100 percent reliably? Being a remote buff this is a queston of great importance.

Both ASA and 10Micron produce formidable mounts, and it is interesting to note the notes from a few more 10Micron users, most of which seem to be on the positive side. For true remote use it really is a good choice.

Want to hear a disadvantage? Well, the momentary switch that turns the mount on and/or off is available in a 3.5mm plug. Naturally, a scripted mount power on/off function is thus easily accomplished. There is, however, no way of knowing if the mount is on or off... Best bet is to wait 30 seconds (longest boot time) and ping it. If it replies it is on and you can pulse the thing to turn it off.

Not a big thing, really

/per


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GIR
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Per Frejvall]
      #6111363 - 10/01/13 02:38 PM

Quote:


I have one question regarding ASA. Does it need homing and does it home 100 percent reliably? Being a remote buff this is a queston of great importance.





I have a backyard observatory and I do homing just in case. Some ASA remote user don't do any homing because they know that the mount hasn't been moved.

Homing really isn't a big deal. Just create one parking position near the homing place, go there and the mount will start searching the homing position. Usually it'll take couple of seconds.
I don't think there is 100 % reliability in astrophotography but for me homing has never failed.
And if it would for some reason, all you have to do is to move the mount close to the homing position with Autoslew key pads and push a button. The mount will automatically start searching the homing position in a certain order ...and will always find it.

Of course if I'd have a truly remote observatory I'd install a camera to see what the mount is doing. Well, actually I do have a camera already because it's kind of neat to sit on the sofa and play with the mount remotely using a laptop


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GIR
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: GIR]
      #6111409 - 10/01/13 03:07 PM

I'm actually doing that right now... taking couple of missing 10 min SII subs and then continue with another target. Here is how it looks like from the living room sofa


laptop view


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psandelle
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: GIR]
      #6111469 - 10/01/13 03:55 PM

The ultimate astro-couch potato!

Gotta love it!!!

I'm keeping track of this thread (and others like it), for next spring when I spring for a new mount. My needs are weighted slightly differently than others (because I'm an idiot, so I need things really idiot-proof. I'm not an idiot when I have time to learn things, but I generally only get once or twice a month to get out under the stars, so the learning curve is sloooooooow, hence the idiocy), but I'm looking at the 10 Micron, the ASA and the PMX. Speed of polar alignment will be important for me, as well. (AP's are great, but there are a few reasons I probably won't go with them, though if I did, it'd be the Mach 1.)

Very cool stuff....

Paul


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famax
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: psandelle]
      #6111821 - 10/01/13 07:32 PM

If polar speed is your main goal, you should consider a mount with polar scope.
So the mach one should fit.


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psandelle
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: famax]
      #6111862 - 10/01/13 07:55 PM

Yeah, but you have to get the AP polarscopes perfect first before you can use them. I also like the extra accuracy of some of these modelling routines to do it.

To show how idiotic I am, I like the fact the PMX has "tics" on the alt/az adjustments to make it easier to get it correct.

Paul


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EFT
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: orion69]
      #6111980 - 10/01/13 09:11 PM

Quote:

If I understood correctly ASA DDM60 or DDM85 is able to do 30min unguided imaging with my FL (<= 1000mm) and GM1000HPS or GM2000HPS can't (I believe it says so in manual).





If you are going to say this, then you need cite the location in the manual. I am certainly not aware of such a limitation, nor would I expect it to be in the manual (and have not found it in either the GM1000HPS or GM2000HPS manuals).


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orion69
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: EFT]
      #6112029 - 10/01/13 09:39 PM

Quote:

Quote:

If I understood correctly ASA DDM60 or DDM85 is able to do 30min unguided imaging with my FL (<= 1000mm) and GM1000HPS or GM2000HPS can't (I believe it says so in manual).





If you are going to say this, then you need cite the location in the manual. I am certainly not aware of such a limitation, nor would I expect it to be in the manual (and have not found it in either the GM1000HPS or GM2000HPS manuals).




Sorry you are right, at the time I wrote that I couldn't find the text.

Here is it now, from GM1000HPS manual:

"5.6 Notes on autoguiding
When properly aligned, and using the dual axis tracking option, the GM1000HPS
mount is able to track stars with extreme accuracy. Usually autoguiding is not
required, and may easily be counter-productive if the seeing is worse that about 1
arcsecond FWHM; in that case, guiding corrections will likely “correct” what are
really movements of the guide star image due to the atmosphere.
With very long exposure times (tens of minutes) tracking errors could show
nevertheless. In this case you will need autoguiding.
In order to minimise the
possible errors introduced by the guiding corrections, you will need to use a very
low “aggressiveness” setting in your autoguiding software, and/or very low
autoguide speed (down to 0.1x) and integration times up to several seconds.
If your alignment is not very good, you may use higher autoguider speeds and
faster integration times in order to track objects, but accuracy will suffer
accordingly.
Note that if you need to autoguide on the declination axis, you may obtain a
slightly better result if you disable the dual axis tracking option, so that the
declination corrections will be always in the same direction."

Edited by orion69 (10/01/13 10:19 PM)


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EFT
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: orion69]
      #6112144 - 10/01/13 10:35 PM

Thanks for finding that. I do think that it says something different though. That is, that no system is perfect and guiding may be necessary at times and depending on the equipment, etc. The 10Micron mounts are very good at unguided imaging, but, like any mount, are not meant exclusively for unguided imaging. There are times when very high magnifications on very deep objects at very long exposures may benefit from guiding, but as pointed out, guiding may actually be counter productive. Not having hands-on experience with the ASA, I can't say what the limitations of the direct drive systems are, but they are certainly different than a hybrid belt/worm system. Beyond the absolute encoder systems, it's a little difficult to make direct comparisons since the tech is so different.

The truly amazing thing about both of these mounts is their ability to measure and correct for problems other than simply tracking precision. Being able to model orthogonality issues and the like truly makes the equipment up in this range amazing. I do think that direct drives are really cool tech.


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GIR
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: psandelle]
      #6112356 - 10/02/13 01:15 AM

I'm starting to sound like an ASA commercial but they do have a fantastic polar alignment routine...

Turn on the laser, check which side of Polaris north pole is located at that time (about 1 degree), and point the laser beam roughly to the north pole.
Open Sequence and choose 3 star polar alignment routine. Sequence will automatically choose you 3 targets, take pictures and plate solve them. After that you'll pick a bright start from south side of Meridian (about the same altitude you're located) slew there and place the start in the middle of the crosshair with the Autoslew key pad ...and push a button.

Telescope will now move away from the star exactly an amount you're misaligned from north pole. All you have to do is to turn the mount (altitude and azimuth knots) and move the star back into the middle of the crosshair ...and you're polar aligned.

You can repeat the Sequence procedure with more stars but the accuracy should be under 10 arcmin with one go.


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GIR
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: EFT]
      #6112390 - 10/02/13 02:00 AM

Quote:

That is, that no system is perfect and guiding may be necessary at times and depending on the equipment, etc.




This is very much true...

I've learned that if you want to do unguided imaging successfully your overall system has to be pretty solid. ASA software can measure all kinds of flexures and hysterisis and I was quite surprised to find out how much flexure my setup had, even I thought it'll be solid like a rock. But there will always be some sort of unwanted movement whatever you'll do.

Sequence can reduce quite a lot of negative effects created by flexure by modeling them out. Especially the MLPT (local pointing model) is very effective. However, even that can't make time flex disappear (temperature changes, relaxation effects, etc.)

I really don't know where the limit is but the longer the focal length is, the more difficult everything becomes. However, with my 600 mm FL I'm not even close to that limit.


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Tonk
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: GIR]
      #6112459 - 10/02/13 04:29 AM

Quote:

I'm starting to sound like an ASA commercial but they do have a fantastic polar alignment routine...




OK I'll do my practical experience bit for the 10u. So this is no different in method and outcome with the GM1000HPS but no laser is actually required. There is even Per's software to totally automate it bar the physical alt/az adjustments

Did you know even the the lowly Losmandy Gemini does this type of polar alignment as well (via model building)? And its also quick. The only downside here is the precision of the mount is lower so measuring final PA misalignment usually is in the +/- 2 arc minute range where as with the 10u and ASA mounts you expect < 0.25 arc minute to be acheived within 15 minutes.

Quote:

You can repeat the Sequence procedure with more stars but the accuracy should be under 10 arcmin with one go.




Did you mean 10 arc sec? The 10u is under 1 arc in one go and gets to 0.25 arc sec in two goes most of the time. Worst I've had in 2 iterations is 0.41 arc sec polar misalign - and even this is good for 10 minutes unguided @ FL 600mm not even using dual axis tracking



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Tonk
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Tonk]
      #6112462 - 10/02/13 04:34 AM

Quote:

However, with my 600 mm FL I'm not even close to that limit.




Too true - its my favourite FL and makes anything look good . At this FL I can get my Losmandy Gm-8 going unguided for 4 minutes (but here about 10% images are tossed)

Hence those unguided times of 10 minutes @ FL 2800mm quoted (way) above are remarkable in my mind


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GIR
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Tonk]
      #6112464 - 10/02/13 04:41 AM

Quote:

OK I'll do my practical experience bit for the 10u. So this is no different in method and outcome with the GM1000HPS but no laser is actually required. There is even Per's software to totally automate it bar the physical alt/az adjustments





OK, why don't you run us through the routine to see how it's done, instead of just saying there is no difference and Per has done something...


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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Tonk]
      #6112468 - 10/02/13 04:45 AM

Quote:

Here is it now, from GM1000HPS manual:




That paragraph doesn't say the 10u cant go unguided for 30 mins (as that is entirely dependent on FL and other factors such as target altitude from horizon etc) . What it is correctly saying is you may have pushed a limit in which case you can autoguide and heres how to set up to autoguide this mount.

So this sentence ...
Quote:

With very long exposure times (tens of minutes) tracking errors could show nevertheless.




.. uses the word could - practically this limit is far more likely to be reached at 2800mm than 600mm depending how well set up and PA corrected etc the mount is. As always you can elect to autoguide your way out of a limit


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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Tonk]
      #6112472 - 10/02/13 04:53 AM

Quote:

OK, why don't you run us through the routine to see how it's done, instead of just saying there is no difference and Per has done something...






Will do - its already on another thread in this forum .. but I have to rush now to uni .. or if you care to use the forum search - I wrote a full setup review back in August

Will put the link here when I get back tonight


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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Tonk]
      #6112482 - 10/02/13 05:19 AM

Quote:


Quote:

You can repeat the Sequence procedure with more stars but the accuracy should be under 10 arcmin with one go.




Did you mean 10 arc sec? The 10u is under 1 arc in one go and gets to 0.25 arc sec in two goes most of the time. Worst I've had in 2 iterations is 0.41 arc sec polar misalign - and even this is good for 10 minus undguided @ FL 600mm not even using dual axis tracking






Yes, I meant under 10 arcmin when using 3 stars and doing it quickly. How much under, depends how careful you are. Of course you can always use more stars or repeat the procedure and then we can talk about under 1 arcmin figures, which are excellent even for permanent setups.

I'm sorry Tonk but I simply have hard time believing your stories how easy and accurate everything is with 10micron. We can always highlight the one time best estimates or tell only half of the story, but repeating things and doing them routinely is quite another matter.
There seems to be a lot of of people who can do unguided imaging with mediocre gear or hit polar alignments on the spot with one go ...if they'd just wanted to.

P.S. just read another thread were you said you've been using 15 stars and three iterations for polar alignment. So we're comparing apples and oranges here.
P.P.S. You'll probably have more flexure on your setup than the polar alignment figures you've indicated.


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orion69
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: GIR]
      #6112525 - 10/02/13 06:48 AM

Guys, just a comment or two about unguided imaging...

If you say that mount is capable of unguided imaging that should mean that it routinely produces long and "perfect" (in my case required 30 min) subs. Routinely means that maybe 1 of 50 is bad, not 50% or 20% or 10%, time when sky is clear is precious.

As far as GM1000HPS goes: in manual says that tracking error is +- 1" in 15 min. That means +- 2" for 30 min, and in my opinion this is too large error for mount to be used for 30 min unguided imaging.
Of course, I'm not saying that something is wrong with GM1000HPS, I'm just trying to figure if it would be useful for my needs. That goes for ASA too.

As for Losmandy Gm-8 being capable of 4 min unguided subs @ 600mm with "only" 10% tossed (which is already too much to be useful), I very much doubt that. Please show us few (not just one) unprocessed FITs of those unguided subs...


In my opinion if mount has absolute encoders it should be used for long time unguided imaging. If mount requires at some point (lets say 30 min and above) guiding, then much better solution would be (for me at least) to buy mount without encoders but with greater capacity (PMX?).

Edited by orion69 (10/02/13 06:50 AM)


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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: orion69]
      #6112545 - 10/02/13 07:10 AM

Quote:

In my opinion if mount has absolute encoders it should be used for long time unguided imaging. If mount requires at some point (lets say 30 min and above) guiding, then much better solution would be (for me at least) to buy mount without encoders but with greater capacity (PMX?).




Knez

As said before, it's not just what the mount can do technically but how well the whole setup is built. I know that ASA mounts can be very accurate and their modeling software is also top notch. Good modeling is actually a very important factor when doing unguided imaging with high res encoders. But it's not enough if there are e.g. flexure issues with the scope and camera.

So I can only tell you that with my setup taking 30 min exposures reliably (if needed) is no problem. However, my scopes are f/3 and f/2.8, so there is really no need for me to do extra long exposures.
What others are doing or what is possible to do, is something I don't want to speculate.


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famax
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: orion69]
      #6112555 - 10/02/13 07:20 AM

That's make sens orion.

Gir, Tonk isn't saying anything wrong, he just mistype
arc/sec and arc minutes somewhere.
By the way you are demandung proofs on 10µ and we were able to give you feedback, not only from us, but from other users.

You are not able to tell us the plus and minus of the asa.
So you are just here to bash 10µ ?

10 arc ' is huge for your polar alignement even for the first step.
After two steps, the 10µ , in the field is usually beetween 20" to 40 ".

It take 10 minutes to do so, after that you can add 12 minutes for your 20 point modelling, and you are ready to go.


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GIR
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: famax]
      #6112565 - 10/02/13 07:34 AM

Quote:

Gir, Tonk isn't saying anything wrong, he just mistype
arc/sec and arc minutes somewhere.
By the way you are demandung proofs on 10µ and we were able to give you feedback, not only from us, but from other users.

You are not able to tell us the plus and minus of the asa.
So you are just here to bash 10µ ?






I think this thread is going to a direction I have nothing to add anymore. As said before, all high end mounts (in right hands) are capable of producing beautiful astrophotos.

P.S. famax I wish you'd read my comments more carefully before jumping into so ridiculous conclusions


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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: GIR]
      #6112595 - 10/02/13 08:09 AM

I was able to do 20 minutes unguided subs on the first clear night a had with my DDM60 at 1380mm.

1) Polaralign with the green laser.
2) Run 3-star pointingmodel (all automated with Sequence).
3) Fine tune polar alignment (once).
4) Create 25 to 50 point tracking model or declination model.
5) Point and shoot 20 min unguided at 1380 mm

Easy does it....


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Tonk
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: jjongmans]
      #6112660 - 10/02/13 09:11 AM

Quote:

I'm sorry Tonk but I simply have hard time believing your stories how easy and accurate everything is with 10micron.




I'm sorry you think this way. But I know exeactly what I have experienced - its an excellent mount that is nice and easy to use. There are certainly others who would back this up.

Maybe you should go and try one for yourself.


This link is my write up of my first night out + Per describes his automated model building tool in the following posts (its free to use)

http://www.cloudynights.com/ubbthreads/showflat.php?Cat=&Board=lxd55&...


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Tonk
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Tonk]
      #6112671 - 10/02/13 09:18 AM

Quote:

P.P.S. You'll probably have more flexure on your setup than the polar alignment figures you've indicated.





Not a lot of flexture at all - I have a very solid connection to my TV85 - its a small scope


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GIR
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Tonk]
      #6112702 - 10/02/13 09:36 AM

Quote:

Quote:

I'm sorry Tonk but I simply have hard time believing your stories how easy and accurate everything is with 10micron.




I'm sorry you think this way. But I know exeactly what I have experienced - its an excellent mount that is nice and easy to use.




Tonk,
Didn't mean to be disrespectful, we just seem to have a different way of expressing our thoughts. Clear skies and many good moments with your new mount.

P.S. you'd be surprised how much flexure all systems have if measured


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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Tonk]
      #6112703 - 10/02/13 09:36 AM

Quote:

As for Losmandy Gm-8 being capable of 4 min unguided subs @ 600mm with "only" 10% tossed (which is already too much to be useful), I very much doubt that. Please show us few (not just one) unprocessed FITs of those unguided subs...





Spending time to get a good PA with the GM-8 is very doable but does take around 2 hours to set up to the level required. PEC training is vital as is carefully off balancing the scope to stop "floating" between worm faces. Its bloody hard to do but I've spent 10 years practicing. When it comes off it works - however its not reproduacble without extreme effort. Another night it might only be be 2-3 minutes unguided. Best setups have reached 6 minutes when above 40 alt.

I'll happily dig out some RAW images + ones for the GM1000HPS (I shoot DSLR) but meantime here is an mosaic image of 8 hours accumulated with 6 minute unguided subs with my GM-8 taken back in 2007. It was an APOD too

http://www.cloudynights.com/photopost/showphoto.php?photo=14659&size=big&...

So after 10 years doing it the extreme hard way - I got a new mount ...


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orion69
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Tonk]
      #6112732 - 10/02/13 09:50 AM

Tonk, PA of course matters, but even if you have perfect PA with low end mount quality unguided imaging isn't really repeatable except with very short subs (usually <1 min).

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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: orion69]
      #6112741 - 10/02/13 09:55 AM

Have you used a GM-8 with the Gemini controller ? - it isn't low end at all. But then its not hi-end either by a long shot. Yes I agree it is not repeatable and that was always the issue for me but it is doable and I've done it many many times over the last 10 years. To date I've never guided!

Also my resolution on the Canon 450D camera sensor is only 2.25 arc seconds per pixel - so I'm not shooting high quality images either. I thought I'd made that clear earlier


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jjongmans
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Tonk]
      #6112753 - 10/02/13 10:00 AM

All depends on image scale whether or not unguided imaging is doable... Short focal lengths (<1000mm) and big pixelsize are more forgiving..

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Per Frejvall
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: jjongmans]
      #6113026 - 10/02/13 12:17 PM

I really have to support Tonk's claim that it is simple. In fact, most mounts are simple to get operational if you know the caveats and have both practice and manual reading to lean on.

The procedure for a 10Micron mount is to roughly align to north using polaris, a compass or the chimney you know is about north. After that you need three stars or "model points". These can be input via the hand controller or, if you operate by means of a PC, via any software that can sync an ASCOM mount. One such software would be my model maker, another CdC.

After a three-point alignment has been completed the hand controller will tell you how much to rotate the Az and Lat knobs, and, of course, the polar alignment error. You then proceed to adjust them.

Clear the model and run another one, this time maybe with a few more points. Most times you can leave it as is after this, but feel free to adjust again if the error is still not to your liking.

At this point you will have a reasonably god tracking model for 10 minutes exposures at around a meter of focal length. The first light moment with my GM2000HPS produced pinpoint stars with around 10 model points and two adjustments of the knobs. Unguided.

Now, one more thing to think of is the stability of the pier or tripod. The tripod I use when I use a tripod is the 10Micron Centaur. Very sturdy, and the distance between one foot and the perpendicular line between the other two is about 80cm with the legs in their unextended position. Suppose it sinks one millimeter on one side... Back to school:

tan(v) = 1 / 800
v = atan(0.00125) = 0.0716 degrees = 4.3 arc minutes

This should give an indication as to the "power of the error". A very small error can throw things off considerably.

What I want to convey is that a model well built can be a model lost if the stability under the mount is not up to par. Still want to use three cement tiles (1'x1') under your tripod legs on the lawn? I thought not

Both ASA and 10Micron mounts do track in both Dec and Ra. This, combined with a modeled "sky", will reduce tracking errors to pure field rotation. Perhaps someone with experience in field rotation calculations can chime in and give us a rough figure on how much a field rotates with a polar error of, say, one minute (which is easily obtainable with 10u and most likely with an ASA as well) during a 10-minute exposure. It is not going to be much (I think) so it is apparently fairly useless to hunt down the last few arc-seconds of polar error (even though it is fun to do so, especially on a fixed pier).

Another two cents, eh?

I really enjoy the simplicity of the 10Micron products!

/per


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Tonk
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Per Frejvall]
      #6113152 - 10/02/13 01:23 PM

OK I have 10 years hard experience using Losmandy/Gemini - the GM1000HPS is virtually identical in set up, modeling and PA align procedures, so it was very easy for me to get used to this mount on my first night. Maybe we should factor that in .. but all the same its is a very easy setup for the experienced or novice user.

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GIR
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Per Frejvall]
      #6113197 - 10/02/13 01:48 PM

I guess there is a need to clarify something even this is getting quite odd.

First of all what I was telling about the ASA polar alignment routine, was a very quick way of having a good basic alignment (in couple of minutes). At the same time Tonk was using far more stars and iteration and wondering why his results are so much better. In another thread he said it took 40 minutes but can be done in less time if practised. So not a very fair comparison.

With all due respect Per what you are telling about 10Micron, ASA mounts can do easily and if you ask me quicker also. If you're using such a rough estimate of north pole there is no way to plate solve right away. However with the help of laser beam (ASA mounts have), you'll get the alignment so close to north pole that plate solve can be used immediately. All you have to do is let the Sequence perform an automated 3 star alignment. And if that's not good enough, you can do another round right away with e.g 10 stars. If done properly, that will put you to under 1 arcmins territory.

It's also a lot easier just to put the star back in the middle of the cross-hair than trying rotate AZ/Alt nobs according to hand control instructions ...at least for me.

I'm sure both 10Micron and ASA mounts are able to do very accurate polar alignments but I think when comparing things a bit more more unbiased attitude would help
Hope I can finally stop commenting this thread


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tomcody
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: GIR]
      #6113300 - 10/02/13 02:44 PM

Tonk & GIR,
I think you guys are both basically saying the same thing, that both mounts have good software, are accurate, and are good mounts to own. Both mounts require the same thing : learning the software that runs them! which as we all know is a little different for each mount made, although they all do about the same things.
After reading this very informative thread, for which I thank each of you for your great comments, I think it comes down for a new purchaser to decide which companies' mount is best for them and their needs. I have made my personal preferences know, but I would be happy to own either mount as judging from your comments (except for mechanical design) there are more similarities than differences.
Regards
Rex
P.S. Tonk, I have a new Losmandy GM-8 being shipped soon ( as I am purely visual now, this is all I need ) and am looking forward to equipping it with the new Losmandy DSC's which should be out soon.


Edited by tomcody (10/02/13 02:49 PM)


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Tonk
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: tomcody]
      #6113330 - 10/02/13 03:04 PM

Yeah - done too.

BTW I'm now down to 15 minutes to get target PA after 2 months of practice . Actually I wasn't wondering why my PA was better I was merely recounting the prodedure written in the manual and how I executed it. I'm sorry I didn't spot you were not using a multistar model - my bad.


Anyway the OP and anyone else interested in these mounts should have plenty to go on now. Right now I'm far more concerned that this dark of teh moon has produced no clears nights at all and the planned present for my wife is getting delayed a month


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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: tomcody]
      #6113331 - 10/02/13 03:04 PM

Here is one question I wanted to ask those using the 10um and ASA.

I have high (we are talking ~35* / ~45* obstacles on E and W sides of my permanent pier. To North maybe 20* but have clear view of Polaris (all these I mean elevation) and South I have lowest - to neighbor rooftop across street.

So my sky is a rectangle N<->S. Will i still be able to benefit from the point / sky modeling if I am permanent mounted?

Thanks for your thoughts on this - this a great thread !


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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: CounterWeight]
      #6113340 - 10/02/13 03:11 PM

Quote:

P.S. Tonk, I have a new Losmandy GM-8 being shipped soon ( as I am purely visual now, this is all I need ) and am looking forward to equipping it with the new Losmandy DSC's which should be out soon.




Neat - you will enjoy it! BTW I still own the old DSC's - kept more for sentimental reasons though they can be used to act a (lower resoution) backup input for the Gemini for when you take clutches off to hand move the scope. My poor GM-8 hasn't been used for 2 months (you know why!)


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Tonk
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Tonk]
      #6113357 - 10/02/13 03:19 PM

Quote:

I have high (we are talking ~35* / ~45* obstacles on E and W sides of my permanent pier. To North maybe 20* but have clear view of Polaris (all these I mean elevation) and South I have lowest - to neighbor rooftop across street.

So my sky is a rectangle N<->S. Will i still be able to benefit from the point / sky modeling if I am permanent mounted?




Yeah this should be OK -

I too have east cut off about 35-40 degrees and west is a bit better at 25. Like you the open parts are north and south (I'm set up in a holiday trailer park in a narrow wooded valley - but its dark!). In some respects this stops you imaging in the rubbish low altitude clagg with all the refraction issues when tracking!


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GIR
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: CounterWeight]
      #6113359 - 10/02/13 03:22 PM

Quote:

Here is one question I wanted to ask those using the 10um and ASA.

I have high (we are talking ~35* / ~45* obstacles on E and W sides of my permanent pier. To North maybe 20* but have clear view of Polaris (all these I mean elevation) and South I have lowest - to neighbor rooftop across street.

So my sky is a rectangle N<->S. Will i still be able to benefit from the point / sky modeling if I am permanent mounted?

Thanks for your thoughts on this - this a great thread !




Hi Jim

As long as you have a view on targets you'd like to shoot, it's no problem. You can modify the pointing model horizon any way you want. So when making models the obstacles in the horizon are automatically taken into account.

Something like this...

Pointing model


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frolinmod
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: GIR]
      #6113388 - 10/02/13 03:34 PM

Quote:

You'll probably have more flexure on your setup than the polar alignment figures you've indicated.



Now there's a realist no doubt with some experience under his belt.


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Per Frejvall
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: frolinmod]
      #6114512 - 10/03/13 02:49 AM

I second that he obstructions pose no problems with either mount. In fact, my balcony setup (where all my work is done) has a terrain mask that looks like in my screen dump of the model maker further up this thread. The grren part is the mask.

/per


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CounterWeight
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Per Frejvall]
      #6115042 - 10/03/13 12:17 PM

Very good to hear Thank you!

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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: CounterWeight]
      #6124078 - 10/08/13 03:15 AM

Thank you all for all the wonderful feedback. I have taken a lot of time to ponder things and I have come to respect both mounts.

I have been swayed more towards the GM1000HPS for the following reasons:
-Complete package available including carry case, this saves a major amount of headache when making the purchase as you don't have to hunt down mount adapters, tripods and so on.

-I've had laptops fail on me before, the ability to run without one is like having a backup. If you get only 6 to 8 nights a year in truly dark sites, you don't want to get there only to find that you can't operate your mount because your laptop is dead.

The bad news is that it's going to take longer than I expected because it turns out that nursery fees these days are higher than what I would have paid to go to college to earn a degree back in 1996.


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orlyandico
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Hilmi]
      #6124080 - 10/08/13 03:23 AM

Hilmi,

last weekend I nearly got worked over because my laptop ran out of battery. Even though I have a mount that doesn't need a laptop, the camera requires one!

so use a DSLR, you counter.. using a DSLR is an option only if you can go unguided (remember, no laptop..) which means you need a very good polar alignment. I don't know about the rest of you but I am totally dependent on the laptop for polar alignment (no view of Polaris where I am).


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Hilmi
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: orlyandico]
      #6124192 - 10/08/13 06:40 AM

Orly,

If you look at both these mounts, their strength lies in their ability to image unguided and both have built in routines for Polar alignment.


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Starhawk
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Hilmi]
      #6124492 - 10/08/13 10:07 AM

I looked at my first photos- round stars in 30 seconds, but I handicapped the GM1000 by not following up with a new mount model. I will probably have a chance for another run Friday with the C11 at f/10 and f/7.5 again (assuming the rain clears out). The f/7.5 reducer made nice tight stars- I'll need to dial down the camera sensitivity to support longer exposures.

-Rich


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Nezar H
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Starhawk]
      #6126717 - 10/09/13 10:38 AM

I have GM4000 QCI 2012 Model , so far I am so pleased with this mount, it's easy as 123 and you are done (easier than my AP1200GTO3),until now I only use the mount for Visual use , for public outreach program (CDK24") in the way next week!! I have 14"HD @ 4meter F.L. and I add 2X Barlow + 10mm EP. I can get the Target every time either on the center or somewhere on the FOV (after 15star model) And not so accurate PA. I have Modded canon 450D try a quick test for 60sec And got round star !! Well I know this is seems totally nothing but there were a Bright smile over my face ! This is only the start to my adventure to Astrophotography world .
I think some will not be happy to know I have high end mount and 24"telescope and I am only Visual and some DSO work, but I should say It was my dream to build observatory for public outreach program on my home! and to use the Instruments to educate and practice by my won some scientific or Astrophotography work Hopefully.. I hope the Mount will not let me down specially when guiding my most nightmare! Thanks.
Nezar.


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Per Frejvall
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Nezar H]
      #6127244 - 10/09/13 03:19 PM

And your QCI is without encoders... How's that for mechanical quality?



/per


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Nezar H
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Per Frejvall]
      #6128509 - 10/10/13 08:20 AM

indeed so happy with this mount .. I hope the official support will be there when I need it , Hopfully Astro-Physics kind customer support .

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tom63
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: GIR]
      #6135557 - 10/13/13 06:24 PM


... opened a new thread.


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Tonk
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: tom63]
      #6142385 - 10/17/13 07:42 AM

Quote:

... opened a new thread.




OK - but put a link to it here please - otherwise we have no idea where it is continued .... you don't even say what it is called

Edited by Tonk (10/17/13 07:43 AM)


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tom63
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Tonk]
      #6142933 - 10/17/13 01:13 PM

sorry ...
http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Number/6137327/page...


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Starhawk
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: tom63]
      #6142978 - 10/17/13 01:38 PM

I have a bunch o new photos taken with the GM1000HPS last weekend with the C11 at f/10 (2800mm FL) where it went an hour with no commands from me to change position. I shot a section of the Pleiades, I'm hoping to have a chance to get some of that posted in the next couple of days.

-Rich


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orion69
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Starhawk]
      #6143294 - 10/17/13 04:36 PM

Quote:

...where it went an hour with no commands from me to change position.




What does that mean?


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Starhawk
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: orion69]
      #6143881 - 10/17/13 10:26 PM

I pointed it at a spot at the sky, and let it track for an hour while taking pictures.

-Rich


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Starhawk
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Starhawk]
      #6144044 - 10/18/13 12:28 AM

OK, my lack of patience got the better of me and I have been playing with my pix with the C11 on the GM1000HPS. So, what I did was start taking images at 10:08PM and stopped at 11:37 PM. This is a sampled stack across that time range. They are 30 second exposures, and the size of the airy disk changed because I was putting aperture masks on in the middle frames (to answer another question). The camera is a Pentax K-5, where the parent frame is 4924 pixels wide by 3264 high. I had to scale it for here, so I have the top right corner included.

Anyway, the mount tracking on the GM1000 appears to have been ostensibly perfect, with a linear error in the X direction to the tune of

49.1 pixels in X and 155.4 pixels in Y, where it slowly increased over time, which appears to be polar alignment error after a three star alignment, a quick align on Polaris, and then a follow-up three star alignment.

-Rich


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Starhawk
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Starhawk]
      #6144046 - 10/18/13 12:30 AM Attachment (25 downloads)

Overall image of M45 while rising:

-Rich


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Starhawk
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Starhawk]
      #6144048 - 10/18/13 12:31 AM Attachment (17 downloads)

Upper right corner crop:

-Rich


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Starhawk
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Starhawk]
      #6144091 - 10/18/13 01:11 AM Attachment (34 downloads)

So, here is a rough time graph. Unfortunately, taking the data with 1 minute resolution leaves the drift of a few pixels in doubt.

Anyway, I expect it will meet Hilmi's 20 minute unguided requirement, but at the moment I am wondering why the exposure will need to be so long.

And by the way, I know these aren't beautiful. That isn't the objective.

-Rich

Edited by Starhawk (10/18/13 01:12 AM)


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Hilmi
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Starhawk]
      #6144182 - 10/18/13 02:51 AM

Starhawk. I don't need 20 min unguided but I do need 20 min exposures for narrow band imaging. I find you really need to go for long exposures especially with SII filter images. Thanks for the feedback

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Starhawk
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Hilmi]
      #6144671 - 10/18/13 11:22 AM

Hilmi,

That makes sense for SII. The mount is very responsive- and at 15 degrees per second slewing, it's really quick and nimble. It has a large pointing model capability. I'm wondering if that may even quietly include c11 mirror flop as a result of motion. In any case, there don't seem to be any sleeping gotchas at this point. The three star alignment with one shot at polar alignment left me with no swirl (the brig star image in the corner is the start of the run and the end if the run stacked, so you can see there was no rotation whatsoever).

I didn't want to end the evening with nothing but engineering images, so I finished with a large series on Orion. I should be able to get that assembled this weekend.

The surprise for me has been how mature this controller is since it isn't one a fourth or fifth generation product from this vendor. They apparently found people with real expertise in this field to get a lot of the internals right.

I should have my last real chance to do major imaging with the mount in early November. Then I'll have to give it back. I expect to miss it.

-Rich


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CounterWeight
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Starhawk]
      #6144878 - 10/18/13 01:10 PM

Rich - great report - much appreciated.

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Starhawk
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: CounterWeight]
      #6144933 - 10/18/13 01:43 PM

Thanks, Jim.

-Rich


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EFT
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Starhawk]
      #6145844 - 10/18/13 11:31 PM

Rich,

Could you explain the blurry look of the start in the upper right corner image? I'm not sure that I understand what this is a result of.

Ed.


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Starhawk
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: EFT]
      #6146609 - 10/19/13 12:25 PM

Ed,

I was doing several experiments during that hour of tracking with the GM 1000HPS. Besides taking photos to get some idea of the mount's movement, I wanted to experiment with the effects from an aperture mask on a C11 (like what happens to coma?) In the one scene, I took images in these configurations:

(1) f/10 at prime focus.

(2) Unobstructed aperture mask series- it covered the entire front of the telescope with a single offset aperture:

(A) 76.2 mm aperture
(B) 50.8 mm aperture
(C) 31.75mm aperture

(3) return to unmasked f/10 prime focus.

So, there was a large increase in airy disk size inversely proportional to the reduction in the aperture, and so I wound up with coverage for the whole time, but with bigger stars in the middle and smaller stars at the beginning and end.

I also to a series afterwards on the Orion Nebula using the Starizona f/7.5 reducer/ flattener which is about ready to post. The amazing thing on that one is how out of 56 frames I took for it, I lost only one to mount movement, where I was touching the camera to start the interval series. I did that two more times and had usable frames. I lost three frames to neighbors' lights coming on.

-Rich

Edited by Starhawk (10/19/13 12:27 PM)


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Starhawk
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: EFT]
      #6146839 - 10/19/13 02:53 PM Attachment (21 downloads)

OK, So here we go- this is the set I did on Orion just as it cleared the local electrical lines. These were made using a stock C11 NexStar 11 GPS XLT OTA with the Starizona f/7.5 reducer/flattener at 2100mm focal length. The series is shot through the 2" Celestron UHC LPR filter. My Baader UHC filter is currently mounted in a Pentax K adapter for Hyperstar. The image is a set of 14X1 second frames, 11X10 second frames (three lost to neighbors' lights), and 27 x 30 second frames (1 lost to me touching the camera). First I have the whole frame reduced for CN (Parent is 4900 pixels wide, so that wasn't happening). The second is the upper left at native resolution, so you can see the stars are round, and satisfyingly coma-free.

The GM1000 HPS was very happily steady for this series- for each interval set, the first frame was made with my hand on the camera, and the mount was stable in 2/3 cases where this was done.

Now, the camera was set to high sensitivity (ISO 25100) for the brightest shot, which does result in background noise. Breaking out the interval timer remote would result in longer exposures. And since longer exposure is more effective than deeper stacking, that's a better answer.

-Rich


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Starhawk
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Starhawk]
      #6146848 - 10/19/13 02:56 PM Attachment (12 downloads)

This is the upper left corner at native resolution. Note the atmospheric chromatic aberration thanks to shooting low to the horizon. I haven't corrected for it to allow an as-shot image to be available.

Also notice how the local sky glow still comes in on the blue channel- that I have reduced, but did so by scaling rather than clipping so the performance of the UHC filter in a broadband light pollution environment is visible.

-Rich

Edited by Starhawk (10/19/13 02:58 PM)


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Starhawk
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Starhawk]
      #6146880 - 10/19/13 03:11 PM Attachment (11 downloads)

This is the center of the field taken just as it was produced by my HDR stacking- I used a Mac program called HDrtist for that step. I am pleased to have 5 trapezium stars come through this way. Kind of an odd thing about the C11 is how no matter what you do the stars are a little blobby with the central obstruction. Overall I would have to say I wholeheartedly recommend the Starizona f/7.5 reducer flattener if you have a plain SCT. What isn't so obvious to me is if the money is better spent on a standard SCT and planning on hyperstar and the reducer/flattener, or if the Edge HD with reducer is a better plan with hyperstar for the same role.

The reason I am putting such a high value on Hyperstar is it is the one configuration of a SCT which really gets to deep magnitudes without relying so much on the mount, and is also the only one which can produce really tight stars thanks to the reduction in focal length.

In any of these cases, the GM1000HPS is certainly proved to be capable to carry a long focal length and I'm not even sure how much weight it will really take since it wasn't vibrating while touching the focus knob of a C11. The obvious answer is more weight than that.

I'd like to hear back on where you all are after looking at my results, which were largely generated because of this thread. I have probably one new-moon night coming up where I can really use this, and for personal reasons, I'd really like to have some pretty pictures to show for it. So, on my own, I'd probably either use it for hyperstar, and go to somewhat longer exposures just to see how deep an image I could get, but that is probably going to be under 5 minutes in any case. Or I could try doing some DSOs with the AP 130 EDFGT, which produces really nice sharp images. I will likely do those with the Astro Tech flattener, which seemed to be effective in my short test earlier. Or, I may put in the AP reducer and see if I have image collapse in the corners or not. In any case, if left to my own devices, I'm probably not going to long focal lengths unless I do another engineering setup (maybe next weekend) and try out chasing satellites.

-Rich


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Hilmi
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Starhawk]
      #6146959 - 10/19/13 04:04 PM

Could you please try a single 5 minute or more exposure at long focal length at any random target? This will give an indication of tracking performance of the mount.

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Starhawk
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Hilmi]
      #6147069 - 10/19/13 05:11 PM

Hilmi,

That shouldn't be a problem. I'll see about doing it on something straight overhead to get atmospherics out of the result. I'll do the full pointing model, so it should be as good as it gets.

What focal length would you like?

-Rich


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Hilmi
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Re: ASA DDM60 Pro vs. GM1000HPS new [Re: Starhawk]
      #6147680 - 10/20/13 12:07 AM

I work at 1600mm so as close as you can get to thag.

Thanks


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