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AP Mach1 and general GEM questions...

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#1 Footbag

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Posted 18 April 2011 - 04:25 PM

So I've had this inkling to upgrade my wedge-mounted CPC-800 to a GEM. I do 99% imaging, but at this point, I think I'm hitting the limitations of my mount. For example, I'd love to get another scope in the 900mm focal length range, but would have no way to mount it to my CPC. I have a WO66, rings and counterweights, but I know it won't handle a 10LB plus scope piggybacked. I'm also a bit frustrated with the corners of my fields on the CPC-800. Even when I use a FR@6.3 I get some coma. As well, I have the older Celestron wedge, and it is extremely poorly designed. I cannot adjust the mount in increments that would allow me to drift align.

So I went to NEAF and got to do some "research". I saw all of the offerings that could fit my potential future optics. I have to say that the AP Mach1 is what really caught my eye. It should be able to handle any optics that might come my way, and it really seems to be best in class.

Now I do have a guiding setup, and would probably use it on the Mach1. I don't know which OTA's I want yet, but would like to cover a few different focal lengths including a widefield scope, a mid FL and a long SCT or similar FL. This mount should be able to handle all of the above.

So my questions are...

Is a mount like the Mach1 capable of long exposures 5-10m unguided? I have a guiding setup, but could save some setup time if it was unnecessary.

Would a better GEM, like the Mach1 have a quicker setup time? It is currently extremely difficult to make the minor adjustments to my wedge to achieve perfect polar alignment. I'd say my off-site setup time is 45m. This is without a drift align.

With a guided setup, how important is the mounts accuracy? I PEMpro'ed my CPC and it has a resolution of 17 arcsec/pixel. 12 arcsec/pixel after I used PEC. This seemed to be better then most GEMs in the $1500 range and that is why I feel like it wouldn't be much of an upgrade to go to one of the mounts in the $1500 class(CGEM, IEQ45, etc...) Of course I would be able to drift align with them.

Now it's quite possible I could cheap out, and buy Celestron's new HD pro wedge. After seeing it in person, it looks much more stable then my wedge, and it also looks like it would put my drift align issues to rest, but doesn't allow me to add or piggyback a larger scope. For the $400, it's pretty cheap compared to my other options.

Coming from a fork mount, I've never had to meridian flip, and I like the idea that the Mach1 can track well past the meridian.

Sorry if this is dragging on, but to reiterate there are a few things I'd like to get out of the new setup.
1. Scalable - the ability to use different OTA's
2. Faster setup including an accurate polar alignment
3. Easily transportable - the Mach1 has a great capacity to weight ratio and breaks down to be lighter then my CPC-setup.

If anyone can help with some suggestions or push me in one direction or the other I'd appreciate it.

#2 Geo.

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Posted 18 April 2011 - 06:33 PM

No mount can expose 5-10' unguided. A minute of two at best. Tom Mathis showed me PEC the chart of his MI-1250 with the optional high precision encoders. This is a $60K mount. He guarantees peak to peak error is less than 5 arc seconds. Anyone else that makes similar or better claims in a geared mount is blowing smoke. Think you'd be happy with the Mach1, but a GM-8 might do the job for less.

#3 Tim C

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Posted 18 April 2011 - 06:40 PM

Hi Adam,

If you want to use different OTAs then you would benefit greatly by moving to a GEM. You can shoot a lot of wonderful stuff using a refractor in the 700 - 900mm range. You can't do better than a Mach 1 in that weight class and the microscopic PE of a Mach 1 will make a very noticeable difference vs. a mount with 20 to 30 seconds PE. For quick set up including polar alignment in a high end mount, I think the Tak EM200 can't be beat because of the super accurate polar scope (I used to own one). I was usually ready to image (polar aligned, guider calibrated, focused perfectly) before it was totally dark. However, the Mach 1 has an even lower PE even before periodic error correction is applied. If you can swing it, I don't see how you would regret a Mach 1.

One thing about an EM200 is that they don't hold their value vs. the new price quite as well as an AP mount and you can get one for around $4,200 used including all accessories. Something to consider if you might be interested in a middle ground.

#4 Footbag

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Posted 18 April 2011 - 06:52 PM

Thanks for the tips. I am also considering a G-11, I think I want a little more room to grow then the GM-8 can offer. Also, my club owns a G-11 that we are considering a Gemini II upgrade on. I would like to play around with Gemini II before I decide, but I think the club is waiting until there is a bit more out there about the new Gemini.

That 700-900mm range is what I'm really missing right now. That is really the reason for my desire to get a new mount.

How important a good PE is if I'm guiding anyways?

#5 gillmj24

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Posted 18 April 2011 - 08:49 PM

At low focal lengths and a light tube the mach 1 can do unguided subs for perhaps longer than 10 minutes. What little PE the AP mounts have is really smooth. That's what you're getting (among other things) with the top end mounts.

#6 David Pavlich

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Posted 18 April 2011 - 09:06 PM

I don't know about how long you can go unguided, but the Mach 1 is a premier mount. The G11 is a good mount, but not in the same class. Hind sight being 20/20, I should've opted for the Tak EM400 which was my other choice. I chose the MI250 because of Larry's reputation and the MI250s excellent track record. However, now MI250 is no longer a viable entity.

At any rate, AP is in for the long haul and will serve you well. There is also the used route. I've seen a Tak NJP pop up from time to time. Arguably, the best 70lb rated mount out there. It's discontinued, but Tak is, as is AP, in for the long haul.

For a mount junkie like me, this is my kind of thread. :grin:

David

#7 lightyear44

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Posted 18 April 2011 - 09:31 PM

Adam. While you were at NEAF you likely noticed the ASA mounts. They are capable of 15-20 min. unguided shots. I've seen images on CN, and had chats with a couple of users who have done it, imaging with Newts. The set-up is a bit long at first, but with practice, it's not too bad. But also a big learning curve at the start. I suspect in 5 years, they will be more beginner friendly. -David.

#8 M13 Observer

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Posted 18 April 2011 - 10:23 PM

No mount can expose 5-10' unguided. A minute of two at best. Tom Mathis showed me PEC the chart of his MI-1250 with the optional high precision encoders. This is a $60K mount. He guarantees peak to peak error is less than 5 arc seconds. Anyone else that makes similar or better claims in a geared mount is blowing smoke. Think you'd be happy with the Mach1, but a GM-8 might do the job for less.


Really? How about an AP3600? 5 arc-sec peak to peak out of the box - mechanical precision - guaranteed. Add on the firmware PEC and it can easily get into the sub 1.5 arc-sec range or less. A friend has one, fully loaded with all the accessories. Very nice mount with incredible tracking. And yes, he routinely runs it without tracking for 3 to 10 plus minute images. My AP1200 was stated as 5 arc-sec or less from the factory. It routinely gives me under 1.6 arc-sec peak to peak without PEC enabled. Maybe this is an anomaly but it is what it is. I generally run 20 or 30 minute subs but I guide. Atmospheric refraction makes this necessary. My AP900 isn't quite as good. It gives me about 4.3 peak to peak without PEC. One of these days maybe I'll record some PEC correction curves for it, or maybe not. I just guide with it too. At any rate, there are high precision mounts that can do exactly what you say they cannot. I am certain that there are some of the Takahashi mounts capable of the same. No BS and no smoke.

#9 jmiele

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Posted 18 April 2011 - 11:11 PM

No mount can expose 5-10' unguided. A minute of two at best. Tom Mathis showed me PEC the chart of his MI-1250 with the optional high precision encoders. This is a $60K mount. He guarantees peak to peak error is less than 5 arc seconds. Anyone else that makes similar or better claims in a geared mount is blowing smoke. Think you'd be happy with the Mach1, but a GM-8 might do the job for less.


Thats some statement to make. A Mach I and GM-8 are not even close to being in the same league.

1) 5-10 minute un-guided subs would depend on FL used. However, very possible on ANY AP mount thats well polar alinged and PEC corrected.

2) As to a 60K mount vs. a 10K mount - incremental improvment shows up big time as you move from 1k-10K mounts. From there on up the gains are small, very small.

Making such bold statements, in this case I think is inappropriate.You are entitled to your opinion, however, I know many here and elsewhere have done 5+ minute un-guided subs. The ME mounts do it everyday.

BTW, you can go to Arnie Rosners site "Grass Roots Telescope Rentals" and do 5 minute unguided subs tonight with a 300 Mewlon and get sub arc second accuracy.

Smoke Blown.......... Joe

#10 D. Perry

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Posted 18 April 2011 - 11:27 PM

Hi Adam,

The Mach1GTO is the premier mount for its class. As long as you come in with the right expectations, you can't go wrong.

Speaking of which, you should never buy a mount with the expectation of not guiding. It can be done with mounts like the ASA DDM60/85, but those are even more expensive, large, and robust mounts that require a computer and special software to run. It can also be done with mounts like the Mach1GTO, AP900/1200, Paramount ME, MI-250, MI-500, etc., but never out of the box. It requires extremely accurate polar alignment, lots of PEC training, correction for atmospheric refraction, and even then you won't always be able to get away with 5-10 minutes at long focal lengths.

The sign of a quality mount isn't just the total amount of PE. It's also the regularity, smoothness, and "slowness" of the PE. Fork-mounted SCTs from Celestron and Meade are difficult imaging platforms because their tracking errors are not only large, but also abrupt and fast. You can get some great images from those scope/mount combos but, generally speaking, a much higher percentage of subexposures must be discarded due to tracking errors (if you're looking to create really high quality images) compared to images taken with a high quality GEM.

The beauty of a GEM is that it's easy to change scopes. On the Mach1GTO, you can carry anything from a small refractor to a 10" RC.

You've probably heard this a million times but it's worth repeating... the mount is the foundation on which everything else rides. If you start with a solid, accurate mount, everything else is sooooo much easier. It fades to the background and just works, which lets you focus on the other aspects of imaging. If you spend more money on trying to improve the fork mount, you'll just be wasting money that could be better spent on a real solution.

HTH. Just my 2 cents.

Best,

#11 M13 Observer

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Posted 19 April 2011 - 12:19 AM

Hi Adam,

The Mach1GTO is the premier mount for its class. As long as you come in with the right expectations, you can't go wrong.

Speaking of which, you should never buy a mount with the expectation of not guiding. It can be done with mounts like the ASA DDM60/85, but those are even more expensive, large, and robust mounts that require a computer and special software to run. It can also be done with mounts like the Mach1GTO, AP900/1200, Paramount ME, MI-250, MI-500, etc., but never out of the box. It requires extremely accurate polar alignment, lots of PEC training, correction for atmospheric refraction, and even then you won't always be able to get away with 5-10 minutes at long focal lengths.

The sign of a quality mount isn't just the total amount of PE. It's also the regularity, smoothness, and "slowness" of the PE. Fork-mounted SCTs from Celestron and Meade are difficult imaging platforms because their tracking errors are not only large, but also abrupt and fast. You can get some great images from those scope/mount combos but, generally speaking, a much higher percentage of subexposures must be discarded due to tracking errors (if you're looking to create really high quality images) compared to images taken with a high quality GEM.

The beauty of a GEM is that it's easy to change scopes. On the Mach1GTO, you can carry anything from a small refractor to a 10" RC.

You've probably heard this a million times but it's worth repeating... the mount is the foundation on which everything else rides. If you start with a solid, accurate mount, everything else is sooooo much easier. It fades to the background and just works, which lets you focus on the other aspects of imaging. If you spend more money on trying to improve the fork mount, you'll just be wasting money that could be better spent on a real solution.

HTH. Just my 2 cents.

Best,


+1 :waytogo: :waytogo:

#12 BlueGrass

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Posted 19 April 2011 - 01:19 AM

I agree. I spent over a year working with my CGEM, trying to get it to accurately and repeatedly guide well. I've had some success but was always working out balance issues when I changed setups or trying various settings in Phd to improve it's guiding performance. Once I got my Mach1, the problems simply disappeared. So far, its performance has been as expected. It truly just moves into the background and lets you concentrate on what you're imaging not on how the mount is performing. I've yet to run a PemPro PEC session or to use the factory PEC data. Once I gain more experience with the mount, I'll do this. For my first few nights of imaging though, I've simply done a 3 to 4 star polar alignment, calibrated Phd with its default settings and that was it. Pretty simple, quick and for a basic alignment, very accurate. These mounts give you something lesser mounts have to be trained to do, if possible. Repeatable, excellent performance and guiding out of the box.

#13 skybsd

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Posted 19 April 2011 - 02:20 AM

Hello,

Thanks for the tips. I am also considering a G-11, I think I want a little more room to grow then the GM-8 can offer. Also, my club owns a G-11 that we are considering a Gemini II upgrade on. I would like to play around with Gemini II before I decide, but I think the club is waiting until there is a bit more out there about the new Gemini.

That 700-900mm range is what I'm really missing right now. That is really the reason for my desire to get a new mount.



Of late, there are more and more folks in this same dilemma concerning the unknowns and uncertainties of the Gemini-II. The merits of the AP Mach-1 GTO are well known and much data is out there that speaks to its capabilities - as well as its PRICE.

Make no mistake about it - There is no free lunch!

If your budget / financial comfort requirements are such that you need to make savings on this purchase, by looking at alternatives like the G11 - you may consider reaching out to the Yahoo Losmandy Owners' and Gemini Users' groups to keep abreast of progress and feedback from ongoing software testing. Then (if you're like me) you'd probably want to wait to see reviews from early adopters who get shipped first-run code before making a decision.

Question for you, though - does a software upgraded G11 match an AP Mach-1 GTO or Tak for your requirements?

Regards,

skybsd

#14 Paul G

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Posted 19 April 2011 - 05:17 AM

No mount can expose 5-10' unguided. A minute of two at best. Tom Mathis showed me PEC the chart of his MI-1250 with the optional high precision encoders. This is a $60K mount. He guarantees peak to peak error is less than 5 arc seconds. Anyone else that makes similar or better claims in a geared mount is blowing smoke. Think you'd be happy with the Mach1, but a GM-8 might do the job for less.


I want some of your smoke. :) Both the AP 1200 and the 3600 are guaranteed better than 5 arc seconds peak to peak without PEC, most are better than that.

#15 Footbag

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Posted 19 April 2011 - 07:53 AM

Wow. Lots of great info here. Thanks.

I see a used Mach1 tempting me on astromart, but I don't think I could jump in that quickly. Plus, I haven't even considered what the primary optics would be for this mount.

I live in a red zone, so what I'm really looking forward to is taking it on the road to darker skies or attempting some narrow-band imaging from my driveway. When I read about these narrowband guys getting 30 minute subs on their AP, I just think "how?". But I can see that it is in a class of its own.

Is it possible to get that type of performance on one of the wooden piers? OR is the upgrade to the portable pier or Eagle a must?



I am a member of the Losmandy group and have been watching the G-11 GII for a few months now. Like I said earlier, I think my club is going to go ahead with one. I will definitely wait to really consider the Mach1 until after I spend some time on the new G11.

#16 coz

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Posted 19 April 2011 - 08:31 AM

I'm thinking about PWT's Pinnacle portable pier as an alternate to AP's. They look awesome and very portable.

#17 jmiele

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Posted 19 April 2011 - 10:26 AM

The AP Pier is VERY stable but takes some breakdown and setp time. It also needs a pretty much level surface to setup on... Joe

#18 Footbag

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Posted 19 April 2011 - 10:48 AM

The AP Pier is VERY stable but takes some breakdown and setp time. It also needs a pretty much level surface to setup on... Joe


That is the one with the cables right? I watched someone setup one and he had a bit of difficulty on an unlevel surface. That may pose a problem.

#19 vahe

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Posted 19 April 2011 - 11:13 AM

Speaking of Mach 1 does anyone here have the Eagle Fording Pier designed specifically for this mount?
Impressions, comments, stability and anything else about this pier would be appreciated.

Vahe

#20 skybsd

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Posted 19 April 2011 - 11:41 AM

I'm thinking about PWT's Pinnacle portable pier as an alternate to AP's. They look awesome and very portable.


The PWT Pinnacles are great - but getting one seems nigh on impossible! :(

Regards,

skybsd

#21 drksky

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Posted 19 April 2011 - 11:51 AM

Speaking of Mach 1 does anyone here have the Eagle Fording Pier designed specifically for this mount?
Impressions, comments, stability and anything else about this pier would be appreciated.

Vahe


Here is a thread from a couple months back from Bluegrass who bought a Mach-1/Eagle combination. He seemed pretty happy with it. I'm betting a PM to him would get the information you're after.

#22 Duncan Kitchin

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Posted 19 April 2011 - 04:24 PM

The AP Pier is VERY stable but takes some breakdown and setp time. It also needs a pretty much level surface to setup on... Joe


That is the one with the cables right? I watched someone setup one and he had a bit of difficulty on an unlevel surface. That may pose a problem.


Thanks for that - I hadn't thought about the level surface issue. Does anybody have any impressions of the AP wooden tripod?

Regards & Clear Skies
Duncan

#23 RAKing

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Posted 19 April 2011 - 04:30 PM

I also have an Eagle pier under my Mach 1 and it works as well as advertised.

I got my Mach 1 a couple years ago and used it on an A-P Portable Pier, then a Losmandy tripod. These worked fine and I never worried too much about the 'uneven' ground under the Pier. I finally saved enough pennies to get the Eagle early this year and it works as well as either of its predecessors. The Eagle is light, easy to move, easy to setup, and it's just as stable. I use it for visual astronomy under my C11 and it can easily handle a C8/AT6RC combo side by side with an AT72 on top. :)

I don't want to sound like an A-P fanboy, but everything I have ever purchased from them has looked great and worked well, right out of the box.

Ron

#24 skybsd

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Posted 19 April 2011 - 04:37 PM

I don't want to sound like an A-P fanboy, but everything I have ever purchased from them has looked great and worked well, right out of the box.


No-one ever got called a fanboy for telling the truth, Ron :)

Regards,

skybsd

#25 JimP

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Posted 19 April 2011 - 04:54 PM

How about eyepiece height using a refractor and the Eagle mount? Anyone have any experience with that?

Jim






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