View Single Post
  #27  
Old 28-01-2020, 11:42 AM
jjjjohn9 (John)
Registered User

jjjjohn9 is offline
 
Join Date: Dec 2019
Location: Sydney, Australia
Posts: 5
Quote:
Originally Posted by Bobbyoutback View Post
Hello John ,
I do own a fast 4" F/5 refractor that's fun to use at lower powers & can show some planetary detail , got it with a AZ3 mount long ago , still cost over $500 at the time of sale .

There are also terrible cheap fast refractors that show rainbow coloured mush images .

Scopes using sub-aperture corrector's needs a longer explanation , try this :

https://telescope-optics.net/sub_aperture_corrector.htm

Cheers
Bobby .
Hi Bobby,
Thanks for your response including the link to the article on sub-aperture correctors
I am just making a comeback to astronomy and needless to say I was way out of my depth in reading that article!
No worries though - I can always refer to it in the future if I really get into the nitty gritty of telescope optics.
Best wishes,
John
Reply With Quote