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Equipment Discussions >> Mounts

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famax
member


Reged: 07/01/07

Re: 10Micron new [Re: GIR]
      #6308158 - 01/12/14 01:26 PM

Yep gir you are right, you have to do another 3 star pointing to verify your polar correction.
But as you know, automatic pointing and solving is just a question of seconds in time (typical cycle time for one plate solve is for my setup :
-slew to a star (or any sky place) between 1s to 15 sec , depend of the travel)
-acquire frame 2s
-plate solve 1s
so for three star it is 1 minute maximum.


anyway, the question was does these automatic routines are
almost as precise as they claim, because reading 15" of pa error on the hand pad is a thing, but reallity can differs.

In that exemple it is proven that it works really good.

To be repeated to avoid the "by luck" factor.


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GIR
super member


Reged: 01/02/10

Loc: Finland
Re: 10Micron new [Re: famax]
      #6308250 - 01/12/14 02:10 PM

I know it's very fast to do another 3-star set, was just wondering why you didn't mention it.

Still have some problems visualizing how you hit 15" with one go...

You set up your mount by eye and point it as close to Polaris as possible(no laser involved). Then you do the 3-star which will give you values how much RA and DE axis are off from target and should be moved. The result will be way off however well you've set up the mount/scope.
After that you manually turn RA and DE adjustment knots and get the 15" error to both RA and DE axis. Something that is VERY challenging to do even with several iterations. And all this with a Newton scope.
I wouldn't call it luck, it's a miracle


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Per Frejvall
sage


Reged: 09/28/12

Loc: Saltsjöbaden, Sweden
Re: 10Micron new [Re: GIR]
      #6308282 - 01/12/14 02:29 PM

I usually get within half a minute, if not after one iteration so definitely after two. If the rig is stable it works.

My procedure is to do the first adjustment with three points in the model, and then run a new model with perhaps 15 or 20 points. If that reports below a minute of polar error I let it go, otherwise I do the adjustment and start a full model with at least 35 points. If no adjustment is necessary I just add another 25 points to the model.

The mount firmware expects you to clear the model after you touch the knobs, so there is always one extra run after you have adjusted.

Currently running a model in Provence on my GM2000HPS:



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famax
member


Reged: 07/01/07

Re: 10Micron new [Re: GIR]
      #6308295 - 01/12/14 02:35 PM

So to tell precisely what is done :
-Wood pier is setup thanks to a compas
-Mount setup with all equipement
At this step it is important to say that the mount use to be aligned the night before, at a same place, but dismounted and reset for this night.
-So once the mount is on the wood pier, it is no very far from polar align : first three stars befor PA correction is
30' error.
-So i proceed for PA correction with centering the star on the CCD thanks to ALT/AZ correction.
-another 3 plate solve (that i forgot to mention as you pointed, gir) give you an estimate of your corrected PA error.

I agree that 15" seems very tight for a one run , but the 6"dec drift during 50 minute tend to prove that it isn't far from that.Or maybe there's a thing i does'nt understand ?


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GIR
super member


Reged: 01/02/10

Loc: Finland
Re: 10Micron new [Re: Per Frejvall]
      #6308321 - 01/12/14 02:46 PM

Per
Your example is very different from what famax was talking about, and any mount with good encoders and software should be able to do that.

P.S. ASA pointing models look even prettier


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famax
member


Reged: 07/01/07

Re: 10Micron new [Re: GIR]
      #6308339 - 01/12/14 02:54 PM

Impresive model per !You have now full sky access in provence !
Gir, the question is : can we trust the model/handpad assesement on the corected polar error.
From what i feel :
Evry setup has its own accuracy : at a certain precision step, the mount given you an estimate that will reamin with its own accuracy.
So for my example , the mount gives 15" , but we have to know the +/- arond this value.

I have to see if there a way to calculate the real polar error given the measured dec drift.

What is the typical PA error you have on the ASA , when
you are on the field ? something between 0" and 1 or 2' ?

Edited by famax (01/12/14 02:56 PM)


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GIR
super member


Reged: 01/02/10

Loc: Finland
Re: 10Micron new [Re: famax]
      #6308350 - 01/12/14 03:00 PM

Quote:

So to tell precisely what is done :

At this step it is important to say that the mount use to be aligned the night before, at a same place, but dismounted and reset for this night.
-So once the mount is on the wood pier, it is no very far from polar align : first three stars befor PA correction is
30' error.




Quite a different story from the first one
It would make all these 10Micron stories a lot more credible if they wouldn't change so much after a bit closer scrutiny.


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famax
member


Reged: 07/01/07

Re: 10Micron new [Re: famax]
      #6308357 - 01/12/14 03:02 PM

Found a page :
http://celestialwonders.com/tools/driftRateCalc.html

that helps :
So a 6" dec drift during 46 ' lead to a 30" error in polar align.

so twice that is reported in the hand pad.
But the model used to estimate this error is only three stars.
Still impressive.


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Per Frejvall
sage


Reged: 09/28/12

Loc: Saltsjöbaden, Sweden
Re: 10Micron new [Re: famax]
      #6308361 - 01/12/14 03:06 PM

Even with a large polar error the mount will track fine unguided. As long as you get it reasonably low the field rotation will be small enough.

/per


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famax
member


Reged: 07/01/07

Re: 10Micron new [Re: famax]
      #6308539 - 01/12/14 04:32 PM

GIR ,
I don't understand, would you please precise your point of view ?
It seems that you do not accept what is described here.
It would be more constructive if you where able to discuss
with smart arguments, and not trying to bash evryone's experience about 10µ.

i remind you that you said the same thing to Tonk.
I feel like you are a bit paranoïd about that... ???


By the way my intention was to find out was kind of confidence we can put in these software PA alignement process, no matter 10µ or asa's.
I gave informations for people to dig in.
I also did ask to you what was the typical thing with asa ddm60.

But maybe i did forget that you are in an observatory, so do not Polar align a lot ?




Edited by famax (01/12/14 05:05 PM)


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Tonk
Postmaster
*****

Reged: 08/19/04

Loc: Leeds, UK, 54N
Re: 10Micron new [Re: famax]
      #6308755 - 01/12/14 05:48 PM

Quote:

It seems that you do not accept what is described here.




Take no notice

Take this on board - 3 of us are here sharing similar experiences - i.e. easy, quick and accurate PA in a short number of model building/PA iterations with a nice portable mount so that's saying something .

As Per notes, if you get a reliable PA error below at least 30" (in whatever number of iterations it needs - I find it takes 2 or 3) and enable the dual tracking mode, your mount will go unguided for some considerable time.

I am more than happy with my imaging results and that's all I need to go on . I've not lost one frame yet to guiding issues - only to clouds, trees and a TV arial!


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GIR
super member


Reged: 01/02/10

Loc: Finland
Re: 10Micron new [Re: Per Frejvall]
      #6309462 - 01/13/14 01:20 AM

Quote:

Even with a large polar error the mount will track fine unguided. As long as you get it reasonably low the field rotation will be small enough.

/per




Per, that is very true.

However, being able to do that (or doing unguided imaging in general) requires a good model of the sky, and building an extensive model takes some time. Another alternative is to build a quick model and add a “local model” into it. That kind of local model uses plate solves taken from the path you’ll be imaging. Very fast and effective way to solve a problem concerning mainly mobile setups but it’s a very good tool for the permanent setups also.

ASA mounts have MLPT for that, and it looks like AP is building similar function to their new software. However, if I've understood it correctly 10Micron mounts don’t have anything similar available.

Was just wondering how 10Micron has solved that dilemma when using their mounts in mobile setups ?


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Per Frejvall
sage


Reged: 09/28/12

Loc: Saltsjöbaden, Sweden
Re: 10Micron new [Re: GIR]
      #6309524 - 01/13/14 03:23 AM

Gir,

The fact that I get unguided imaging with as little as ten points in my model sort of does away with the need for a local declination model, but I do see the point of it. I do not know if ASA handles the local model differently, but in the 10Micron case, building a model with points along the same dec is not a problem; the question is how it affects the sky as a whole as the actual points are not used when tracking, just the resulting set of model parameters.

As per ASA's CEO's video interview regarding the local model, he suggests using 20 points along the same declination. If I do a 20-point model I get unguided imaging all over the sky and the process is quick. Autoslew and Model Maker probably build the same size model in the same amount of time, especially when considering that both will need to make the same number of exposures and do the same number of plate solves. There is just no way around that. They both have approximately the same slew rate, 13°/s for DDM60 and 15°/s for GM1000HPS.

When I get the time I will try a model with all points along the same declination and see what happens.

I am currently expanding Model Maker to do offline modeling, i.e. expose first and then plate solve the whole bunch and download them as a batch to the mount. The time saving will be minimal, but still; the firmware support is there, so...

Sorry, but i definitely do not share your view of Autoslew being "pretty". To me it has the same look and feel as TheSky or some incarnations of Linux desktops, i.e. not very consistent and a bit too bloated. But hey, that's just me

/per


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GIR
super member


Reged: 01/02/10

Loc: Finland
Re: 10Micron new [Re: Per Frejvall]
      #6309562 - 01/13/14 05:01 AM

Per

I don't know were that "20 points along the same declination" comes from because the use of that many MLPT points is really not necessary in most of the cases. Besides I know that the results are a lot better with a specific MLPT model than with a general model including the same amount of points.
Anyway using MLPT is dependent on the time you're imaging a target not some specific number of plate solves ...which is pretty logical if you think about the rotation of earth. I'm getting excellent result with only couple of MLPT points even when imaging several hours. It really makes a difference especially when imaging with longer focal lengths.

It's nice that you like to compare Autoslew/Sequence software to your Model Maker. So let's make one thing clear...

As far as I know, 10Micron doesn't really have any kind of software of their own to support automated modeling or using a PC in general. Hand pad is their main tool for operating the mount. All the software development we've seen and talking about here has been developed by you Per ….and not 10Micron ?

If that is the case, I really respect your effort. Without all that work 10Micron mounts would be able to take advantage only few of the benefits included into using high resolution encoders and unguided imaging. I’m sure all 10Micron mount owners are very grateful for you for that.

So comparing Model Maker to ASA or AP software is a bit odd and doesn't really give a truthful picture of what's going on IMHO.
What concerns me is that such an important aspect of using a high end mount has been left for the mount owners’ responsibility. Other high end mount manufacturers are spending a lot of time and money building sophisticated software packages for their customers.


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Tonk
Postmaster
*****

Reged: 08/19/04

Loc: Leeds, UK, 54N
Re: 10Micron new [Re: GIR]
      #6309637 - 01/13/14 07:11 AM

And what is the real point of all this sniping and rather pathetic backhanded complements GIR?

I notice that anywhere on CN where a 10Micron mount gets mentioned its always you who step in and say its all rubbish. A take it you are a real authority on 10Micron stuff so we should be listening?

Quote:

What concerns me is that such an important aspect of using a high end mount has been left for the mount owners’ responsibility.




Rubbish!

I'm a pragmatist - If I'm getting excellent results without using some gismo then I don't need to know about that gismo. I use my 10Micron in the field, I don't use a laptop or any external computer to control it or set it up. Its just a scope, my camera, and an intervalometer for automating image acquistion sequences. I haven't a clue about plate solving - not really sure what this is either. Do I need to know?

I'm getting excellent results and that is all I need to care about. So I'm not bothered about all this stuff you seem to asume is absolutely necessary. I only get bothered when there is a problem to solve.

Yeah - so I seem to be able to use what comes in the box, don't need a computer, don't need Per's stuff, don't need this "plate solving" thing and it all works exceptionally well and I create nice pictures. What a mount!!!!


But you will tell me different ....


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GIR
super member


Reged: 01/02/10

Loc: Finland
Re: 10Micron new [Re: Tonk]
      #6309692 - 01/13/14 08:05 AM

Quote:

And what is the real point of all this sniping and rather pathetic backhanded complements GIR?

I notice that anywhere on CN where a 10Micron mount gets mentioned its always you who step in and say its all rubbish. A take it you are a real authority on 10Micron stuff so we should be listening?

Quote:

What concerns me is that such an important aspect of using a high end mount has been left for the mount owners’ responsibility.




Rubbish!

I'm a pragmatist - If I'm getting excellent results without using some gismo then I don't need to know about that gismo. I use my 10Micron in the field, I don't use a laptop or any external computer to control it or set it up. Its just a scope, my camera, and an intervalometer for automating image acquistion sequences. I haven't a clue about plate solving - not really sure what this is either. Do I need to know?

I'm getting excellent results and that is all I need to care about. So I'm not bothered about all this stuff you seem to asume is absolutely necessary. I only get bothered when there is a problem to solve.

Yeah - so I seem to be able to use what comes in the box, don't need a computer, don't need Per's stuff, don't need this "plate solving" thing and it all works exceptionally well and I create nice pictures. What a mount!!!!


But you will tell me different ....




Yes I will...

...because that might be the way you’re using your mount for imaging. However, most people taking astro photos use CCD cameras, computers, automated focusing, need to plate solve, and use many other gismos (like you call them). And that’s actually where high resolution encoders and unguided imaging really shines, and makes your life easier.

So what you call rubbish is actually what most people are doing when imaging


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Per Frejvall
sage


Reged: 09/28/12

Loc: Saltsjöbaden, Sweden
Re: 10Micron new [Re: Tonk]
      #6309693 - 01/13/14 08:06 AM

Tonk,

Couldn't agree more. It works WITHOUT a computer and it doesn't need any software at all. The other solutions out there are dud without a PC.

Gir,

I developed Model Maker because I saw a personal need for it. People like Tonk here do fine without it as did I for the first couple of months.

All my software does is automate a process that is available as manual IN THE FIRMWARE. The tracks model assisted with only power available. No other mount does that as far as I know.

As for other parties' software packages that are delivered with the mount... I started software development in the early 70's and have worked extensively in hat line of work. Let me just say that I am not always impressed by the packages floating around out there, neither in therms of robustness nor stability.

/per


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GIR
super member


Reged: 01/02/10

Loc: Finland
Re: 10Micron new [Re: Per Frejvall]
      #6309706 - 01/13/14 08:16 AM

Quote:

Tonk,


...All my software does is automate a process that is available as manual IN THE FIRMWARE...
/per




Per

You said the magic word ...manually. Most people buying high end mounts don't want to do things manually and/or are using remote setups

As said before you've done very good work with the Model Maker, it's just a shame that 10Micron (as a manufacturer) can't provide any kind of software for their customers who don't want to play with the mount manually.


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guyroch
Vendor (BackyardEOS)
*****

Reged: 01/22/08

Loc: Under the clouds!
Re: 10Micron *DELETED* new [Re: GIR]
      #6309785 - 01/13/14 09:02 AM

Post deleted by guyroch

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EFT
Vendor - Deep Space Products
*****

Reged: 05/07/07

Loc: Phoenix, AZ
Re: 10Micron new [Re: GIR]
      #6309831 - 01/13/14 09:28 AM

I thought this was a thread about 10Micron?

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