View Single Post
  #32  
Old 03-04-2013, 01:28 PM
bloodhound31
Registered User

bloodhound31 is offline
 
Join Date: Aug 2006
Posts: 4,628
Quote:
Originally Posted by Shiraz View Post
You don't just get "the Barlow" that works on all imaging systems - your Barlow must be chosen to match both your scope and the chip that you decide on - there will be quite different solutions for different cameras and scopes.

As I see it, with that scope, your options are:

D..K21 618 - well tried and dependable - fairly large pixels so you will need a final FNo of about f28 - get there with about a 4x Barlow with your scope (suggest 3x with extension tube). Then you will have a setup much like the one that Franck uses so effectively.

QHY5L2/ASI120 - quite new cameras, but some imagers are producing very good results with them. these have smaller pixels than the DBK/DMK and do not need so much magnification - 2.5x Barlow is about right with your scope (suggest 2x with extension tube).

Neximage5 - relatively untried, but has high spec chip - has tiny pixels and only needs a final FNo of about f11. - you can get there with a 1.5x Barlow.
Thanks again Ray. Big effort mate. Sorry I'm slow to convince sometimes. I just don't want to spend big dollars and get the wrong combination.

Anyone have any reasonable grounds to dispute this? If so, why?
Reply With Quote