From: "Mel Bartels" 
To: "atmlist" 
Reply-To: "Mel Bartels" 


>>>
The difference between the
1/8th and 1/16th errors ended up being visible only to experienced
observers and only on a rare day when the sky was sufficiently stable to
allow the use of such a fine mirror.
<<<

I think we are talking about different things here.  This is using the
focused image to discern differences between mirrors of different
qualities. The star test that I refer to and that most refer to is using
the out of focus star image, both inside of, and outside of, focus to
discern the mirror's figure by inspecting the distribution of light in the
defocused disk.

Mel Bartels

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