RE: ATM Round Two

["Banich, Howard" <Howard.Banich@nike.com>]

Hi Rick,

Here's a site that will help you make a collimation tool:
http://zebu.uoregon.edu/~mbartels/kolli/kolli2.htm#mkpeephole

But there are several site out there - try a search via Google.

How high a power to use for star testing depends on how accurate a test you
want to do. But first you need to have well collimated scope since more
magnification will also magnify collimation errors. Once you scope is well
collimated and cooled close to ambient temperature, use as high a power as
the seeing will allow, which is hopefully over 400x. You don't need darker
skies for this, but you may want to use Polaris for star testing since it
will stay put long enough to have a good look at the in-and-out-of-focus
diffraction rings. Waiting for steady seeing will also pay dividends, but
that may only mean you have to keep the scope out all night and star test in
the hour before dawn.

Ultimately, the best verification on the quality of your mirror is how much
you enjoy the in-focus images, so unless you are truly pursuing optical
perfection don't get too caught up in minor differences in the
in-and-out-of-focus star images. If they're pretty close and the in focus
images are sharp and satisfying then you're all set.

Howard
Portland, Oregon

 -----Original Message-----
From: 	Rick Maillet [mailto:bucko_62@yahoo.com] 
Sent:	Monday, August 26, 2002 7:08 AM
To:	atm@shore.net
Subject:	ATM Round Two

How high power does one have to use for star test,I
can see the stars with 75x and 150x but 250x is
difficult, it not really dark skies here, (why do
people leave there outside lights on..when they are
asleep...lol)
is 150x powerful enough for star testing or should I
head for darker skies and try for 250x???
 
Now I know collimation is critical for a 10 inch
telescope and I have to make a collimation tool too
insure me the best views possible.

So I have to find a link to the design of a
collimation tool.
anyone know of one?

here is a silly question,but if the moon looks so
fantastic even at high power, I bet that does not
verify the quality of the mirror in itself, does it?
                                                     
Thanks 
                                                      
Rick