In a message dated 4/6/2005 9:31:46 AM Pacific Standard Time,
ml@No-Spam writes:
It appears you dont do much star testing.
Richard Ozer has probably taken part in literally hundreds of star tests of
mirrors at the Chabot Observatorys telescope makers workshop where he is an
instructor.
Serious testers like Dobson and
others use an artificial star, which needs not be more than a christmas
tree ornament on a tree illuminated by a laser pointer, or a distant
powerline insulator in the sunlight (Dobson's favorite
I wouldn't consider a person who kicks the rocker box as a means of
collimating a '
serious tester.' Not to say he hasn't done an incredible service to the
amateur community.
Actually, I would challenge anyone to figure a parabolic mirror using
whatever indirect tests you want, and come up with a perfect image at the
eyepiece without doing a confirmatory star test! Ha ha.
Mike
Are you saying that the star test is the only way a person should check a
mirror that they are figuring? There are many variables introduced when you've
got a mirror installed in a scope that could introduce errors in a star test.
Yes, a star test is a great and important way to test a system, but in my
opinion, a carefully conducted test of a mirror will give lots of useful
information, especially if you're grinding your own mirror.
Richard Navarrete
Received on Wed Apr 6 09:57:18 2005