Thread: aperture fever for visual observation
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  #18  
Old 27-03-2009, 01:30 PM
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Roger Davis
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Join Date: Nov 2004
Location: Sydney
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Once you've looked through a 27" ... hmmm ... back to the 13.25".
Think of it as surface area a = pi*r^2 you can allow for the secondary size as well.
After the ETX90 go to an 8", it's worth it.
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