Telescope Reviews: Question About Cats

Well, it depends on what you mean by "some AP".

First, I've seen some say that the C11 is a bit large for the CG-5 mount (the one on the GT model) and that you really should use the CGE mount if you're going to have that big a scope on it. I don't have personal experience so I'm just repeating what I've seen on other posts. I think if you really want to compare visual vs. AP, you should be thinking about the CPC vs the CGE for that size scope.

But back to the "some AP". You can actually do a reasonable amount of AP on the CPC mount. The problem with an Alt/Az mount is that it does not rotate with the sky, it only moves up/down and left/right. So if you take exposures longer than 15 seconds or so, you'll see field rotation in the images. But, many people use software that allows them to take hundreds or thousands of short exposure images and "stack" them to create the final image. the software rotates the various images so they match up to produce the final. This works well for bright objects like the moon, planets and globular clusters. I'm not sure how well it works for DSOs since I don't do AP (yet :-).

If you want to start out with visual and then move up to this kind of AP, the CPC mount is a good choice. Another option if you want to move up to more serious AP after a while, is to buy a good solid wedge to use with the CPC. To get one that will be substantial enough to do the job right, think $800 or more. But that would allow you to use the CPC mount and do long exposure guided AP.

But, if AP is your primary goal, you probably should go with the CGE. The downsides of an Equitorial mount is that it requires extra setup time and can cause you to go into some weird positions to do visual observing. But it does a great job for long exposure AP.

Before you decide which way to go, you might want to read the recent article on CN by Rod Molise called "Uncle rod, I want to Take Pictures":

http://www.cloudynights.com/item.php?item_id=1837

Serious AP can cost a bundle including the mount, specialized imagers, etc. In addition to the monetary investment, there's a large time investment both for learning and for doing. So you should consider if you really want to go that way before investing in a very expensive mount that will not be as easy to use or as comfortable to view as a fork mount.

-Dan

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Celestron NexStar 8
Telrad
Celestron 40mm and 25mm eyepieces
Baader Hyperion 13mm, 8mm, 5mm eyepieces
2x Barlow
Meade 0.63x Focal Reducer/Field Flattener