Thread: Sagittarius
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Old 13-12-2020, 09:49 PM
Zuts
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Join Date: Mar 2007
Location: sydney
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Quote:
Originally Posted by raymo View Post
Something is wrong somewhere, because light gathering power of optics
is the diameter squared, so 10mm is 100 and 54mm is 2376, so the 54mm has 23.76 times the light gathering power of the 10mm, which seems a bit
ridiculous. I imagine that somebody with a younger/better brain than mine will help us out.
raymo
You are correct, it's (D1/D2)^2, not that I have a better brain, and certainly not a younger one

I guess it sounds a lot but then a 60mm Tak will give good views and images, not sure of the mileage you would get from a 10mm scope...

Cheers
Paul
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