Thread: ASTRO: M-51
View Single Post
  #3  
Old April 1st 08, 06:22 PM posted to alt.binaries.pictures.astro
George Normandin[_1_]
external usenet poster
 
Posts: 1,022
Default ASTRO: M-51


"Richard Crisp" wrote

I took the liberty of making a tweak or two......


Richard,

I cranked up the 'blue' at the end just because I like blue!

I also did not spend too much time processing this one. It was very dark
that night so there is little background to work with. I need more data on a
night with better seeing.

With other versions of this I used the color balance suggested by
Astro-Don's color calculator, but unfortunately he never got response data
for the STL-1301E, so I've been using "ST-10" or "ST-9".

I also did another version balancing with one of the stars in the field.
The Navy USNO 2 star catalog shows one to be nearly the same red & blue
magnitude, so I adjusted for that. In the end I'm just going to have to take
the time to calibrate this system on a G-2 star...... but not on a night
when it's 14 F and I have 6 other people bugging me to see what I'm doing
and to look thru the other scopes! I had people bumping the scope, turning
the lights on without warning, etc. It's still better than dealing with the
coyotes on my own.

I've been trying a "Rob Gendler" method on the past few images: create a
RGB from the color data, process and smooth out the noise, then split it
back up into color channels that you use to make the LRGB. The jury is out,
but who can disagree with Dr. Rob????

I can e-mail you a full 48-bit color fit file if you can handle that. The
jpg was compressed of course, and reduced in size.

George N