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Old 24-05-2013, 09:30 PM
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RickS (Rick)
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Join Date: Apr 2010
Location: Brisbane
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Quote:
Originally Posted by Shiraz View Post
Fascinating Rick. It looks like the process overcomes star "fattening" due to increasing CCD non-linearity at high signal levels, as well as outright clipping when the ABG cuts in. Is this a reasonable observation? Regards ray
Ray, I don't think it helps a lot with the "fattening" but it does replace the truncated top of the star profiles. Probably a second best strategy compared to your use of short subs with a very low noise camera.

Quote:
Originally Posted by bojan View Post
I am using this (or equivalent) technique all the time - when adjusting curves in DPP.
They are always steep at low intensities, while at the top they are more flattened but never completely flat (so, they are logarithmic-like).
Interesting, Bojan. I've never played with DPP. So you're doing something similar with a non-linear stretch?

Quote:
Originally Posted by RobF View Post
Good post Rick. I've never gotten around to seriously trying this except ad hoc for objects with really bright stars in the field (e.g. M42). Make a lot of sense and good of you to show some detail in the process.
Thanks, Rob. 3dplot makes it easy to experiment with these things and visualize the results. It's so hard to come by data when you don't have a permanent obs and live in the city so I feel obliged to try to make the best of what I can get!

Cheers,
Rick.
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