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Old 14-05-2020, 12:14 PM
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mental4astro (Alexander)

mental4astro is offline
Join Date: Jun 2008
Location: sydney, australia
Posts: 4,902
Hi Jack,

The answer to your question is, as always, it depends...

Now, both scopes are a native f/10. That as such is not really an issue with today's astro cameras. The physical difference between the two scopes is the Edge has a built in field flattener. What this means is if you use a camera with a large chip size (not talking pixels, but the actual size of the sensor), an image taken with the Edge scope the edges and especially the far corners of the pic all the stars will be nice and sharp. In the standard SCT like your 11", the stars will start bloating out because of the effects of coma this scope design had inherent to it.

This is not fatal, and there is a simple solution for your 11" - using an f/6.3 focal reducer-corrector will eliminate the effects of coma plus give you a faster focal ratio of f/6.3

If you use a camera with a small chip, you may not see any coma in the pics with the 11". But you will be using the full focal length of the scope.

There is also a focal reducer for the Edge scopes, but it is not the same lens as used for the standard SCT.

As for the wedge, i cannot say. It certainly is a robust bit of kit, and I am sure many people are happily using one. For many purposes it most likely will be just fine, with the greatest source of problem being alignment accuracy, as with any eq mount too.

As you would know, each scope has its own appeal, pros and cons. It's not for me to tell you what you MUST do, just explain the ins and outs of each.

I hope this helps.

Other people may have other thoughts too.

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