Selecting a new Mount

[boggsd]

Hello everyone,

After much thought I've decided that will try to upgrade my mount this winter from the Celestron AVX. I am looking for something with at least a 40 lb weight capacity at the up most price of $1800. This next mount will be used for imaging with an Edge 8" HD, some autoguiding set-up (i'm not completely sure yet on specifics but the camera wil be a qhy-5L II; you may also try to help me out with that too), and a Canon t2i. Now I have been looking at the Celestron CGEM/ CGEM DX and the Orion Atlas/  Atlas Pro but I'd prefer to find something a little cheaper then the "superior versions" of those mounts so I have more flexibility with the budget to get items to start autoguiding too. The Skywatcher AZ-EQ6 seems quite well also I've only recently got introduced to it. Any feedback or suggestion is greatly encouraged. 

[ollypenrice]

The Canon 550D (I think this is what you have under the T2i name?) in an 8 inch Edge would be trying to image at an incredibly optimistic 0.44 arcsecs per pixel. Even if your seeing will allow this (will it?) you would need a phenomenally accurate autoguiding system and mount to make that possible. This isn't a resolution I'd be trying to acheive on a budget mount. I've imaged at 0.66 arcsecs per pixel on the excellent Mesu 200 but going down to 0.44 would be a very tall order on any mount. General chat about mounts tends to focus on weight, which is often not the problem at all. Accuracy is often the problem. At 0.44 arcsecs per pixel you can bet your bottom dollar it would be the problem. You are in real danger of trying to image at an unreachable resolution and would do better with a shorter FL and faster scope which would give the same resolution more quickly and give a much wider field of view. I'd rather say this than not say it.

Olly

[boggsd]

The Canon 550D (I think this is what you have under the T2i name?) in an 8 inch Edge would be trying to image at an incredibly optimistic 0.44 arcsecs per pixel. Even if your seeing will allow this (will it?) you would need a phenomenally accurate autoguiding system and mount to make that possible. This isn't a resolution I'd be trying to acheive on a budget mount. I've imaged at 0.66 arcsecs per pixel on the excellent Mesu 200 but going down to 0.44 would be a very tall order on any mount. General chat about mounts tends to focus on weight, which is often not the problem at all. Accuracy is often the problem. At 0.44 arcsecs per pixel you can bet your bottom dollar it would be the problem. You are in real danger of trying to image at an unreachable resolution and would do better with a shorter FL and faster scope which would give the same resolution more quickly and give a much wider field of view. I'd rather say this than not say it.

Olly

What kind of camera would recommend?

[ollypenrice]

The problem is that the Edge is incredibly slow (F10 at native and F7, I think, with the expensive reducer) and has a long focal length. (Why a telescope manufacturer would make a deep sky astrograph with a focal ratio of F10 is a mystery, at least to me.) This is a rather deadly combination for DSLRs which thrive on fast F ratios and have small pixels (generally getting smaller still by the year.) To my mind only monochrome CCD cameras make any sense with this scope. CCDs are available with larger pixels and mono versions can bin their pixels 2x2 to speed up capture, certainly for the colour layers. A mono CCD is the only way I can think of to work at a tolerable speed with the Edge. The Atik 11000, for example, has huge 9 micron pixels and would give 0.93 arcsecs per pixel which is at least reasonably practicable. I think the Edge would cover the huge chip, too, certainly at native. I believe the reducer provides a smaller corrected circle so an Atik 4000 with reducer would give you 1.09 "p/p, again reasonable, and in both cases the colour could be binned 2x2 without affecting quality to any great extent. This would be way, way faster than using a DSLR.

If you want to stick with the DSLR are you wedded to the idea of the 8 inch Edge? A much faster scope would serve you better with a DSLR.

Olly https://ollypenrice.smugmug.com/Other/Best-of-Les-Granges/22435624_WLMPTM#!i=2266922474&k=Sc3kgzc

[pete_l]

What I would suggest is you have a look on Astrobin and see the sort of results that people are getting with an Edge / Canon combination. If those are the sorts of image you would be proud to produce, yourself, then go ahead. If you were expecting something else, then it's time for a re-think.

The Az-EQ6 does seem to have impressed a fair few people.

[Owmuchonomy]

To add to what Olly and Pete say it is about what you expect to gain from such a combination. Here is shot at F10 through my Cel 9.25" taken with my Canon 600D purely to catch a Supernova, not as a DSO gallery shot.

However, stick a bright object like Venus in front of the same combination and it produces more pleasing results maybe.

[Earl]

ID be more inclined to get a imaging refractor, something like the ED80 with reducer and then get a webcam type camera or maybe a better option for the sct to do luna and planetary imaging, (the full moon is not DSLR friendly).

Long Focal length imaging is doable but takes a huge amount of effort without the right mount and camera, which will blow your budget.

Unless of course you have your heart set on it, but id do plenty of research before investing into it as out may find it will require a much larger budget with a mount and camera upgrade.

[boggsd]

The main reason I've been using the canon is that we already had it, and the adapters to an edge was not too expensive. My plan was to never stay with it forever and to upgrade the main camera I'd use very soon (was to be this year or next). The mount issue is that lately I've been having troubles with the AVX; random locking in the axes and a GO-TO system that never quite worked ever since I've got to name a few... It just does not seem as a long-lasting, flexible platform like the others I've seen and mentioned. The Edge I got due to the main prospect of imaging smaller-deep sky objects and planets. I felt it was a good median platform for smaller to mid-range objects. With a low focal ratio guidescope, I could perhaps try to get a better range? I do also have a astromaster 114mm I don't use for imaging though it's not much of an improve with a F/8.77 (as of celestron). A change in optics was not in the immediate plan, it was a thought after purchasing a new mount and a new central camera. The plan is right now was to purchase a new mount and an off-axis autoguiding rig (due to the scope with the canon already being so back-heavy that off-axis would only complicate (though only slightly)) and to purchase a CCD camera next year, the AVX is just annoying me and I'm not sure how another year with it will go. (Several recommendations have been to upgrade the AVX). 

[boggsd]

Thank you all for the suggestions and feedback so far, very appreciated by the way

[boggsd]

opinions on the skywatcher quattro newtonian series?