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Eyepiece question

Started by mcvman, 10/16/2011 09:55PM
Posted 10/16/2011 09:55PM Opening Post
I realize most Astromarters are mainly concerned about modern eyepieces, but I still have a problem understanding why the primary image of the telescope objective falls between the lenses in a Huygenian eyepice. I am sure the answer is very simple but I cannot see the cause for it, when comparing diagrams of common older eyepieces. Is it the lens spacing? The relative focal lengths of the 2 lenses? or what? Thanks for humoring me.

Cheers,
Dave K.