7: Readout Noise from calibration, example 5
Do you calibrate your images with dark images?
Or even also bias images?
Every calibration increase the readout noise.
If taken many sub darks and sub bias it will reduce the noise, but zero images will give zero readout noise from them, but how?
You can try dithering instead../tutorial-dithering/tutorial-dithering.html , it works well on my Canon 6D camera under some circumstances.
Low static pattern is crucial from camera.
It still give noise, I will calculate that later.
Test with 0, 10, 25 sub images and look at Step 3: S/N single image.
How much did the total S/N change?