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Old 25-10-2021, 09:11 AM
astro744
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astro744 is offline
 
Join Date: Apr 2007
Posts: 1,244
Quote:
Originally Posted by Rod-AR127 View Post
Geez l am missing something here.
How do you know the field stop of each EP? Or is it set at 27 or 46 respectively.

A 15mm EP of 68°AFOV, in a 1200 FL scope.
TFOV= Field stop 27mm / 1200 X 57.3 = 1.289°?
So it does not matter the 15mm Or the 68° AFOV.
All the 68° EP's from 3mm to 33mm with a 27mm field stop will all have the same 1.289 TFOV?
ARRGGGHHHH.
Field stop diameter for Tele Vue eyepieces can be found at https://www.televue.com/engine/TV3b_page.asp?id=214

Lots of other advice here https://www.televue.com/engine/TV3b_page.asp?id=154

Note from the table eyepieces with the same field stop diameter give the same true field in a given telescope. Magnification and apparent field of view is what will vary with different eyepiece designs.
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