Help with picking a mount
Posted 25 February 2013 - 09:58 AM
If the CGEM DX will work with the Meade for AP I'll be fine for now but if not I have another question. I've seen a C14 mounted on a CGEM DX before for visual use and was told it works just fine. I'd love to have one someday and would probably like to try astrophotography with it as well. So if I buy a new mount for my Meade I'd like to get one that will also handle a C14. Which mount would you recommend. The CGE Pro at $5000 seems to be the best deal and its advertised to carry 90 lbs. Does Losmandy or Astro-Physics make anything in this price range that would work better for AP with a C14? I know Losmandy makes the Titan but its over $7300. Would the G11 be much better than what I have? The Titan is out of my price range and I'm not familiar with the Astro-Pysics stuff. Just know its expensive! Thanks for any opinions you might offer on these 2 questions.
Posted 25 February 2013 - 12:54 PM
Posted 25 February 2013 - 01:34 PM
I dont know about celestron but I know that if you can afford an Astro Physics mount go for it and in my opinion you will be happier with the astro physics more than with the bigger OTA
uhhhh..I just checked. I dont think so Even their cheapy only supports 45lbs (less than my CGEM DX), cost $6350 and doesnt include a host of very important items like a regulated power supply, saddle, tripod, etc. I'm sure it would be as high (probably more!) as the Losmandy Titan once all the other needed stuff was added on. So I guess those are not an option for me. Looks like the CGE Pro or G11 are my only choices and I'm not sure the G11 will be enough of an upgrade over the CGEM DX as far as capacity goes.
Posted 25 February 2013 - 02:23 PM
Posted 25 February 2013 - 03:09 PM
Posted 26 February 2013 - 12:45 AM
Posted 26 February 2013 - 01:03 AM
The 2nd issue with SCT imaging is focal length. My C11 EdgeHD is 2800mm without the focal reducer or 1980mm with it. APO Refractors are so popular for imaging because of the short to moderate focal length and clear aperture. You AT65EDQ has a focal length of 420mm. Unless you are using Hyperstar you are working with a SCT focal length of 2000 to 3910mm and the accuracy of the mount has to improve to match.
I don't want to discourage your mount shopping, but consider the added challenges when imaging at long focal lengths with mirrors that move to focus.
Posted 26 February 2013 - 01:08 AM
To me it would seem like spending $5000 dollars just to use your Meade versus your Celestron isn't going to provide as much performance return for the investment.
Have you thought about watching out for a used AP 900? The difference between any Celestron mount and an AP mount is really amazing. With the new replacement for the 900 GTO coming out this year, I suspect there will be some nice used 900s for sale at the end of the year.
Posted 26 February 2013 - 01:23 AM
2) the CGE Pro is extremely large and heavy (about 100lb I believe for the mount head, tripod, and counterweights)
3) based on Celestron's own figures the periodic error with PEC enabled of the CGE Pro is about 3" - the periodic error of the Mach1 with PEC enabled is < 0.5"
4) the Mach1 weighs 30lb, you won't get a hernia
5) you will probably never sell a Mach1 (unless it's to get a bigger AP or Software Bisque mount!) but a CGE Pro... not so much. Celestron resale values are in the toilet.
6) the Mach1 is a better deal IMHO than the EM200. I was waffling between these two. The Mach1 has a better handset, lower periodic error, it has PEM, and is overall a much more modern mount for basically the same cash.
7) However... the current Japan PM and Bank of Japan head are committed to devaluing the yen to improve Japan exports. This will have a direct effect on Tak prices. If the EM200 price drops below $4000 (it is $6200 odd right now) it would be worthy of consideration.
8) the EM200 is overloaded for a C11 (as per Jerry Lodriguss)
9) the Titan is very heavy, and the report in the other thread is 1.6" periodic error after PEC. Still nowhere close what a Mach1 can do.
Sorry for the long list. Get a Mach1. You'll never regret it, guaranteed.
I just got one after a parade of mounts (a Vixen GP, a CGEM, and a - 20 year old - AP 600). Yes it was big bucks for me. But it's the first mount I've had that exceeded my expectations. No complaints whatsoever.
And I did not spend over $7000. Buy a used Mach1 for $5500, this will usually include the saddle, the small weight shaft, and some weights. You'll need an ADATRI ($60) to connect it to the tripod of your choice.
In extremis you can use the CGEM DX tripod (!) with the ADATRI, you will just need a plate with an M12 hole in the middle to attach it to the CGEM DX tripod. Then the ADATRI screws to the plate.
I have my Mach1 on a $75 Celestron tripod from the 1990s. It fits with zero adaptation - this is the ADATRI bolted directly to the top of the Celestron tripod
Amazingly in spite of the low-rent tripod I can do 10-minute guided subs at 2350mm with my C9.25. Also interesting - the PE does not degrade with payload (unlike my CGEM). The maximum I have put is only about 35lb however (C9.25 + a variety of accessories). I believe that's close to the limit for my cheapy tripod.
A good alternative is a Takahashi NJP Temma 2.
These always go for under $5K and can carry about 70lb for imaging. An overall better mount than the CGE Pro.
I so wanted to buy one of these, but the CFO decreed that it looked too antique. The NJP after all is based on the JP before it - a design that dates back to the 1980s or was it late 1970s..
It has no periodic error correction, but the raw PE is well under 5" (generally around 2" to 3"). You cannot do GoTo from the handset - which is only a directional pad - you need a PC to command GoTos.
Like the AP mounts, the Tak Temma only does a 1-star align. So it will not compensate for polar misalignment. If your polar alignment is out, GoTo's will be inaccurate.
Personally if you can live with the weight (more than a CGEM DX) the Tak NJP is probably the best deal in premium mounts out there. Just be aware that it is discontinued and has numerous electronic limitations.
Used EM200's don't go for much less than $4000 and have less payload than the Mach1. So I would not go for an EM200 if an NJP were available.
Posted 26 February 2013 - 11:26 AM
I suppose I am good with what I have for now but I'm ready to move up from imaging with my AT65EDQ. I have plenty to image with my AT8IN and C8 for now but I just researching mounts to increase my image scale when shooting very small objects such as planetary nebula. I'd love to pick up a C14 someday and know I'd love to try imaging with it at f/6.3 and a focal length of 2460mm+. The 10" Meade is 2500mm at f/10 but I dont know about imaging at f/10. Just wanting something I know I'd never outgrow. Thanks for the ideas and comments guys!
Posted 26 February 2013 - 12:11 PM
They come up rarely for around $5K used, and, now that Gemini II is available, is once again a viable platform.
I'm still loving mine,~3 years (or is it 4 now?) after getting it used (I was the 3rd (!) owner).
Posted 26 February 2013 - 12:19 PM
is the very limited latitude adjustment range - I live at 1 degree latitude.
Also it is very heavy. But in this regard a better choice than the Tak NJP because you can still buy a new Gemini II and motors if your electronics die. (albeit with a long, long wait, since naked Gemini II's seem to be backordered everywhere)
Posted 26 February 2013 - 01:09 PM
Posted 26 February 2013 - 07:05 PM
The longest focal length that I used the Mach1 with is 2000mm with the 10"RC and my subs can be as long as I want, using an OAG.
i must add that on nights of less than average seeing my FWHM isn't so good but that's true for both mounts.
The NJP polarscope is more accurate than the one on the Mach1 but the NJP's expires in 2015.
Posted 26 February 2013 - 08:46 PM
Posted 26 February 2013 - 11:48 PM