Thread: Galileoscope
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Old 27-10-2018, 06:47 PM
N1 (Mirko)
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Join Date: Oct 2013
Location: Dunners Nu Zulland
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Alright, so Venus was a no-show today (the current crescent is spectacular), but the thick, bright cloud cover today provided a good canvas for an exit pupil comparison between both scopes. Photos were taken a minute or so apart, same settings, same lens on the DSLR. They show the back end of the scopes, with a 40mm TVPL in place, giving an effective exit pupil of 4mm. They also illustrate what the exit pupil really is - an image of the objective (plus the inside of the OTA).

Flocked unit on the right. On the left, we see lots of light where it doesn't belong. The halo-like feature is light bouncing off the inside of the draw tube, so flocking that part alone would appear to get rid of most of the scattered light outside of the effective exit pupil, thanks to the baffles. Notice however the brighter central area as compared with the flocked unit. This may be due to light being reflected off the areas between the baffles and somehow affecting the light cone itself. Notice also the crappy flocking job, my first
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Last edited by N1; 27-10-2018 at 06:58 PM.
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