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Auto Histogram stretch using stellar color calibration

Posted: Wed Oct 08, 2025 9:52 pm
by roelb
I have experienced that the histogram is stretched automatically, even if it is turned off in the Stellar Color Calibration.
Very strange: not always...
This was using the Folder Monitor Camera.

Re: Auto Histogram stretch using stellar color calibration

Posted: Thu Oct 09, 2025 1:00 pm
by admin
Hi Roel,

I suspect that what is going on is that the calibration is adjusting the background subtraction amounts for each channel (this always happens, regardless of the adjust stretch option), and the change in background subtraction can change the output image significantly because it moves the histogram peaks left or right - this applies even if the yellow stretch curve is unchanged.

On my to-do list I have a plan to make it so that when you adjust the background subtraction (moving the histogram peaks), it would automatically change the stretch by a matching amount, meaning that this sort of effect would largely go away (and it would make adjusting the background subtraction much easier as you would not need to tweak the stretch after every background subtraction change).

cheers,

Robin

Re: Auto Histogram stretch using stellar color calibration

Posted: Thu Oct 09, 2025 9:19 pm
by roelb
Thanks Robin. Much appreciated!