View Single Post
  #3  
Old 27-07-2008, 05:59 PM
Satchmo's Avatar
Satchmo
Registered User

Satchmo is offline
 
Join Date: Dec 2005
Location: Sydney
Posts: 1,883
Quote:
Originally Posted by miki63au View Post
The 6" achro used to be legendary because of higher contrast than mirror based systems (for equal price). How is nowadays the quality of this doublets?
Miklos, If you put a 6" off-axis aperture stop on a 12" Newt you'll see superior images to a 6" F8 Chinese refractor. I have two 6" F8 Achromats and consider that the star images are looking soft and distinctly yellowish with a 12mm eyepiece, due to Chromatic Aberration.

A stopped-down Newt has no such limitations. Its great to be able to remove an aperture stop on a larger Newt, when you want to see some detail in deep sky objects.
Reply With Quote