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Zoom binocular exit pupil
Hi there.
Just wondering if anyone knows how a zoom binocular can maintain its exit pupil even at high magnification?
For instance the Celestron 20-100x80 has an exit pupil of 3.5mm, which would be fair enough at about 23x magnification. But at 100x would you end up with an exit pupil of 0.8mm? Or is the 3.5mm maintained across the entire zoom range, and if so, how?
Cheers.
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