Author Topic: How is the exit pupil size of an eyepiece determined and is there an optimal siz  (Read 266 times)

James Bagby

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I'm getting ready to buy a fixed length focal length eyepiece or two for use in both a 140mm-f/7 refractor with a 980mm focal length and also in a 100mm-f/9 refractor w/ 900mm focal length and in research "exit pupil" size is referenced. Is that the same as the size of lens of the eyepiece? Is there an optimal exit pupils size and if so how is that figured out?

thank you!