[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: CD5 Saturated Sources again

On Wed, 29 Dec 1999 13:17:18 -0800, Chris Albertson <calbertson@logicon.com> wrote:
*>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.

Here's why I am up-front on my ignorance on coma and optical effects.
There is an effect as I describe, that is a "fact" of sorts. Check
Disk #5, images H3R1438.***. These images show the cross pattern I
mention. Is it "coma"? is it "barrel distortion"? What DOES matter
is that 1) we all use the same language to describe these phenonema,
2) we agree on its characterizations, 3) we find solutions.

But we gotta have numbers, our work will advance as we have the numbers.

Herb Johnson

Herbert R. Johnson              http://pluto.njcc.com/~hjohnson
hjohnson@pluto.njcc.com         voice 609-771-1503, New Jersey USA
             amateur astronomer and astro-tour guide
     S-100 computer restoration, parts, manuals as "Dr. S-100"
   rebuilder/reseller of compact Macs for your computing pleasure