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Old 10-01-2009, 11:55 PM
Zuts
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Join Date: Mar 2007
Location: sydney
Posts: 1,836
Quote:
Originally Posted by Jeff View Post
Could it be that you're disturbing the mount ever so slightly when changing filter colours?
This happens to me as well. For example I image with a ST2000 XCM which is a 2 megapixel camera. Over the period of say three hours taking 10 minute subs my images 'move' about 10% top to right and need to be cropped out after stacking.

I guess this 'pixel creep' is caused by inaccurate polar alignment. The guiding can still keep the guide star centered but over a three hour period it 'wanders'.

On a large format camera or DSLR this would not be a problem but on my camera you lose nearly 10% of the image after stacking.

Cheers
Paul
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