[APML] IC 443 with raw scan examples

["Mike Cook, AF9Y" <mwcook@concentric.net>]

I'm still experimenting with techniques to determine optimum
exposure times for E200 in varying light pollution conditions.
Here is a processed example of IC 443 in my polluted southern
skies:

http://www.webcom.com/af9y/ic443.htm

I've included the three raw scans with each one normalized to
a 20 20 20 RGB dark frame boundary.  Based on the density data
and slides provided by Jason Lewis, I believe the optimum exposure
should occur when the sky fog reaches aprox 70 to 100 for the RGB
values after setting 20 for the dark frame.

The 77 min and 60 min exposures were at the lower limit of the
optimum range.  The 77 min image had a better Signal to Noise
compared to the 60 min.  Unfortunately, I did not make longer
exposures to prove that the Signal to Noise levels off.  The
increasing pollution with lower elevation is another variable.
  

I am interested in hearing from anyone else that can do
similar tests with E200.  It would also be interesting to collect
data on how long it takes for a dark site exposure to reach the
70 level.




Mike Cook, AF9Y
http://www.webcom.com/af9y
mwcook@cris.com




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