Thread: Qe vs aperture
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Old 14-10-2011, 08:10 PM
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RickS (Rick)
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From a pure light gathering POV and taking some simplifying assumptions...

Going from 45% QE to 68% QE gives an increase in sensitivity of about 1.5 times (actually 1.511111111...) That's equivalent to an aperture increase of just under one and a quarter times [sqrt(68/45) or approx 1.229].

So, 4" aperture at 68% QE is equivalent to about 4.9" at 45% QE, 12" aperture at 68% QE is equivalent to about 14.75" at 45% QE, etc.

Cheers,
Rick.
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