Thread: star colours
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Old 16-11-2014, 03:41 PM
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Shiraz (Ray)
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Shiraz is offline
Join Date: Apr 2010
Location: ardrossan south australia
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Originally Posted by alistairsam View Post
hi Ray,

I use Maxim for stacking and startools for stretching and post processing.
Maxim has the option of CIELAB or RGB or HSL when combining LRGB.
I occasionally use CCDStack, results are very similar.
I haven't explored options in startools yet, might have to ask Ivo about how to maintain star colour during processing.

I've uploaded an unprocessed, uncalibrated 5min bin1x1 B sub here
are you able to check if the stars have typical values.


just a point - when stacking, make sure that you use either average or median - not sum.

Your image looks normal to me, with a few saturated stars. Ran Startools digital development over it (96%) and it behaved as expected, with compressed bright values, but no additional saturation. As Geoff has suggested, select the stars with a mask and boost the saturation and you should be able to restore some of the colour lost by compression in the stretching process. Also try Rick's idea of blurring the chrominance a bit to bring some colour into the saturated regions.

All the best, Ray

Last edited by Shiraz; 16-11-2014 at 05:11 PM.
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