Breakthrough #2

[Tom Droege <tdroege@veriomail.com>]

Looks like I have made the circle around bright stars go away.

The one thing different about the TOM2 and TOM3 is that I assembled the 
lenses for them from the new un-chipped ones that I had made to replace the 
crunched ones.  (For those new to tass, 39 nice 400 mm fl f/4 lenses were 
stored in my garage over a Chicago winter.  When I went to get one for the 
next telescope, I found that many of the lenses were crunched from the way 
they were glued in the lens tube and the temperature change.  I had 
replacements made for the crunched lenses.)

The V lenses look OK looking at stars.  The I lenses see bright stars with 
big rings around them.

I assembled a lens from the old chipped parts.

This lens shows little or no rings around the bright stars.  When I put the 
lens together I checked the radius of the optics.  The new lenses and the 
old have the same curvature.  So they got that part right.

The only thing I can imagine is that they somehow made the I lenses from 
the wrong glass.  This is hard to imagine since lenses in the same position 
in these lens assemblies are made from the same glass.

I guess I will be on the phone Monday to try to see if the optician can 
tell me what happened.

I probably have enough of the old lenses for the next couple of telescopes, 
so there is time to fix this.  I am tired of optical problems.  ;^(

Tom Droege