Re: CD5 Saturated Sources again

[Chris Albertson <calbertson@logicon.com>]

hjohnson@pluto.njcc.com wrote:

> ...they have a "cross" pattern as a background
> that is darker in the corners. I think THAT is coma spreading the
> background out at the corners. 

Here's what I think.  Fire away if you think I'm wrong.

I don't think coma would spread out the background.  Assume that the
background is made up of a large number of point sources.  Each
point would be imaged as a coma but they'd all overlap.  You'd have
the same amount of total light.

If the image scale changed as a function distance from the center
(pincushion/barrel distortion) then I would expect the background
to vary because the density of those point sources depends on the
image scale.

-- 
  Chris Albertson

  calbertson@logicon.com                  Voice: 626-351-0089  X127
  Logicon, Pasadena California            Fax:   626-351-0699