Progress with MaxDSLR


Sep 5, 2006

 


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#25898 Sep 5, 2006

Sorry for the cross posting, it just seems that the "DL" part of the

Maxim groups is a bit busier. I just wanted to share my latest

progress I've made.

-Tom



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Friday night I took a whole bunch of images of NGC 7331 and also

managed to get most of them without too much drift from the RA of my

scope. I set my guide camera at 2.5 second exposures rather than the

5 seconds I've been using before. I got some advice that a longer

exposure would minimize the scope from autoguiding on the atmosphere -

which make sense - but then when I got one of those ugly 1.8 pixel

offsets, I'd have to sit there for 5 seconds before it would try to

correct for that. So, there are times that 5 seconds is good and

others when 3 or less is better. I stacked 16 images of the galaxy

group and came out with this as the raw stacked final version --



www.eastsideastro.org/observatory/temp/ngc7331-raw-stack.jpg



There is some vignetting in the image, some blue color around the

middle, and a couple of dust bunnies. Easy to fix. Here is the final

result after fooling with Photoshop for a long time..



www.eastsideastro.org/observatory/temp/ngc7331-16stack-sept1.jpg



Ok, this brings up anothe question. When I'm doing the RGB

conversion, I think I've got the red and blue possibly screwed up? I

am using an unmodified Canon 10D, so the red channel will ususally be

weaker, and more blue would show up. Now I get the opposite, red is

very strong, and blue is very weak. I did turn down the red channel

from the recommended 225 setting (things seem VERY red when I set that

to 225). I'm sure that is my problem, and I may be feeling

intimidated by the excess red in the raw stacked frame before I save

it as a .tiff. Then again, for some reason the blue is weak - which

is usually the dominant color with my camera, but I still end up with

a very strong red channel.

I do have a lot of light pollution in my area, so I'm sure I'm picking

up a lot of the familiar pink stuff. I'm guessing that I would need

to stray from the recommneded 10D RGB settings?

....but just how much, that is the problem.



Slowly getting there!



Tom

Renton, WA

www.eastsideastro.org/observatory



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