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Old 10-01-2014, 11:29 AM
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allan gould
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allan gould is offline
 
Join Date: May 2005
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Quote:
Originally Posted by cometcatcher View Post
That doesn't sound right. f10 is 2/3 of an f stop dimmer than f8. A full f stop would require double the exposure, so 2/3 f stop make 66% more exposure needed?
Kevin
I think you didn't see that I was comparing a 10" and 12" at different f ratios. But thanks any way.

Quote:
Originally Posted by RickS View Post
Approximately 1.57 times assuming a 50% obstruction by diameter.
Thanks Rick, I thought that it would be in the ball park you and Clive have given.
Allan
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