TASS - PSFs

[droege@wwa.com]

I have been focusing and adjusting the VCO.  The best I can do is:
  Camera                      PSF    
V  (Camera O)                 3X9
R  (Camera 1)                 5x7
I  (Camera 2)                 7x7

The PSF seems to stretch out much more than can be explained by the 
VCO setting.  I can get numbers like 3x5 for V with the optimum VCO
setting for V, but then the R and I numbers get much worse.  I assume
that the minimum area for all three is what I want to work for??  What
say Mike?

The PSF above is what comes out of Star in the star list.  

How do these numbers compare with what the rest of you are seeing?

It seems to me that I could attempt to improve the focal length for V by
adding some glass.  This would add two surfaces with the resultant light
loss.  It would also require a lot of fussing.  I figure it is not worth
it.

BTW, now that I have three cameras all looking at the same spot, I can 
compare stars found.  It is roughly what I would expect.  The I camera
finds more stars.  The I filter has roughly twice the bandwidth of the
V and R.  But it also sees more background light.  This is a tough game.
With the sky background limit, twice the light only gets you Sqrt(2)
more S/N.  This holds true for larger diameter lenses.  S/N goes up 
with the diameter, so it is just not worth the effort to go to more
expensive lenses.

Tom Droege