Binoviewer  Comparison Page


This table below is a direct ray trace of how a particular clear aperture and optical path will interact with a set of eyepieces.  In the columns below it is broken down into three different f/ratios.  These f/ratios cover many important applications and represent a best case scenario to a worst case scenario.  F/11.5 is a typical f/ratio for an SCT when using a binoviewer.  F/7 is using the binoviewer a Refractor or SCT with a focal length reducer (FLR) in place giving roughly a 40% reduction off of the f/11.5.  F/5.2 would represent a worst case scenario when a telescope such as a Dob is used with an optical corrector. 

                      The Figures below are the Full optical path of the binoviewer considered. EX: A 20mm plossl in the scopes focuser in contrast to the eyepiece holder of the binoviewer. The Optical path figures below are the difference in mm.

Bottom Clear Aperture Total Optical Path F/11.5       Fully Illuminated spot area and mm's  Squared F/7            Fully Illuminated spot area and mm's  Squared F/5.2         Fully Illuminated spot area and mm's  Squared
45mm      Elite  184mm 29mm.    660.2 22mm        383 12mm       113
40mm    VP40  150mm 25mm     490.6 20mm        314 12mm       113
28mm  114mm 16.5mm  213.7 12mm        113 5.5mm     23.7
26mm  115mm 16mm     200.9 8mm            50 4mm      12.56
25mm   BN25  100mm 16.5mm  213.7 12mm        113 5.3mm        22
22mm  115mm 11.5mm  103.8 5.5mm      23.7 0.0mm          0

Newtonian Diagonal Analysis

by Mel Bartels   <<<Check figures here


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