View Single Post
  #14  
Old 15-04-2011, 07:54 PM
gregbradley's Avatar
gregbradley
Registered User

gregbradley is offline
 
Join Date: Feb 2006
Location: Sydney
Posts: 18,183
A 10RC would be tempting. A different type of image but these GSO RCs are awesome instruments. Longer focal length and probably a bit heavy.
I am not sure what your mount is but you'd probably want a decent mount for that sort of scope. Long focal length is harder get round stars with autoguiding so everything has to be upped in quality and accuracy.
But it does open up a world of galaxy images which is appealling.

Also not sure what the pixel size of the QHY8 is. You ideally strive for around .66 arc seconds /pixel with an assumption of 3 arc second seeing which is common and in some cases it would worse than that.

I have just been trying out my ML8300 camera on the CDK17 and I was surprised to find it had quite a bit worse resolution than my Proline 16803 camera. I put that down to smaller pixel size and less sensitivity (not by much though) and smaller well depth (how many electrons a pixel can hold).

So that .66 becomes more important with a longer focal length scope.

The WO132 would be a nice wider field more forgiving instrument.

You could also put a Tak 1.6 extender on it and get a longer focal length for images as well. Another advantage of good refractors, they are potentially 3 focal lengths - short with a reducer, native and long with a barlow or Tak extender.

Greg.
Reply With Quote