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Old 15-03-2010, 11:22 AM
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avandonk
avandonk

avandonk is offline
 
Join Date: Aug 2005
Location: Melbourne
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Quote:
Originally Posted by Paul Haese View Post
Duncan how does that look now? I could not get all the defocus out but this is a compromise between sharp and slightly out of focus. Unless any gurus have any tricks they care to reveal?

Paul do you dither between exposures? By stacking randomly dithered upsized (use cubic interpolation x1.4 to x1.60) images you effectively double the pixels on your sensor. This works very well when undersampling ie the tiny dim stars. Small or dim stars actually can be recorded at better than the Dawes limit with a high quality optic. At your image scale seeing of course is a factor. Richardson Lucy deconvolution if used sparingly also helps.

Blue stragglers are now thought to be stars that have collided and combined into a higher mass and hotter star. I have often wondered about the red one clearly visible in your image.

Bert
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