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Old 12-02-2009, 09:03 AM
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toryglen-boy (Duncan)
Scotland to Australia

toryglen-boy is offline
 
Join Date: Jan 2009
Location: Canberra
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Quote:
Originally Posted by Terry B View Post
For visual use the f number is not very important.

ya think?!?!?

i would say that for visual astronomy the F ratio is still important, maybe not as important as photography, but still rather important anyway

The F "size" will help to govern such things as eyepiece magnification, field of view, the actually physical size of the OTA, on a reflector it will have a big input on how easy it is to collminate your scope, and how much coma it suffers from, and on a refractor it has alot to say about the amount of CA.

i would say get as short as possible without compromising on quality, for a reflector i wouldnt get anything shorter than F6, anything less and colmination has to be exacting, and coma might start being a hassle, although the trade off is a wider field, and a more portable scope.

its up to you !!


Last edited by toryglen-boy; 12-02-2009 at 09:05 AM. Reason: cant spell !!
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