Thread: Aperture
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Old 01-12-2013, 08:23 AM
glend (Glen)
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Join Date: Jun 2013
Location: Lake Macquarie
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Simply calculate the area inside both circles (mirrors) using the formula A=3.14 x the radius squared, and then subtract the smaller one from the larger one. Take that difference and divide by the smaller number to get the percentage increase in the larger mirror - hope that make sense. A quick calculation shows the area difference is 30%, so the larger mirror would have 30% more light gathering area.

Last edited by glend; 01-12-2013 at 08:35 AM.
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