wrote in message
. com...
http://www.pliniocamaiti.it/test_main.htm#C11

How 'bout them radial spokes. They are almost certainly caused by the
radial slots cut into the glass master-block that deforms the corrector
plate during polishing, presumably as the block approaches or exceeds
its usable life (the block wears as it is cleaned. This link is
obviously a severe case, whereas they are just hinted at in the
interferogram from baader. The two C11s I have owned certainly did not
look this bad, more in line with the quite decent .029 rms of the
German result.


I am not cursive in German or Italian. Attempting to understand what both
websites are saying, it seems that the Baader test image with the 8 spokes
is a phase contrast test image , while the Italian one is just an out of
focus star test . I've seen similar images with spokes from Celestron sct
scopes and the spokes contrast is highly dependent on magnification, how far
out of focus and if the scope has reached thermal balance. Couldn't draw any
conclusion if it's good or bad based on how contrasty the spokes are .

best regards,
matt tudor