Live Stack output jpg affected by stretch setting?
Stacking program, astrometric (plate) solver, fits file viewer
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Hi I want to clarify one point. When I do Live Stacking, I will make some contract and stretching to the image displayed so as to get a better visual impact. My thought was that this stretching is a "Viewer Only" effect and the stacked jpeg output file should remain the same as "raw" without being affected by the setting in the viewer. However it seems that this is not the case. I have attached 2 live stacking jpg of M34 I observe last evening. One with the black point set at 0, the other with black point set at 2500. White point and stretch amount is the same in both cases. It comes out very different. Is this expected?
Seems that only 1 image is allowed per post? This is the image with black point at 2500
Hello Herbert. Yes the stretch influences the jpeg output. Note jpeg is only 8 bit so the unstretched 16 bit camera image will reduce in quality if you store it in 8 bit only. The camera images are 12 or 14 bit but stacked the grey levels will soon increase to the full 16 bit.
Best is to save the live resulting stack as FITS from the viewer once your happy with the stack.
Han
Thanks for quick answer, I don't realize that I can save it in other format. It seems that a TIFF format might fit my case better. Great help.
From the viewer you could EXPORT it to 16 bit PNG or 16 bit TIFF or 32 bit FITS. The jpeg output was created as a special request for somebody having a network to share it live.
Cheers, Han