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Old 19-01-2020, 04:26 PM
Bobbyoutback
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Bobbyoutback is offline
 
Join Date: Oct 2009
Location: Broken Hill
Posts: 283
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Quote:
Originally Posted by jjjjohn9 View Post
Other problems with the "Black List" are that price should be taken into account. Some of the small low focal ratio (f5/f6) refractors could be ideal starter scopes given their portability and presumably attractive price. Satisfactory Planetary views could be obtained with the addition of a barlow and filter.
The list is quite useful as a guide but would be improved if the criteria were better explained , eg What does "corrector mean?
John
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 .
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