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Old 21-09-2020, 05:51 PM
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gregbradley
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Join Date: Feb 2006
Location: Sydney
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Can't say I have done a specific test but I don't think that its exactly the same.

Telescopes don't focus all their light onto an eyepiece or a sensor. A lot goes past it hence the ability of a reducer to focus more of that missed light onto the sensor giving a wider field of view.

Eyepieces complicate the scene though. How much of the total light collected is focused into that eyepiece? Not all, how much though I don't know but some is missing the eyepiece or the sensor for sure. Perhaps not enough to make a big brightness difference but noticeable in imaging.

Greg.
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