|
The effectiveness of stacking lots of subs also comes down to whether or not your swamping read noise.
If you’re not getting above the noise floor then you’ll get to a point where you’ll smooth data above the noise floor BUT never get fainter.
100x60s will not be beaten by 12,000x1s even though it has half the amount of total integration.
The quality of your calibrations will also determine stacking depth. If you don’t calibrate then Fixed Pattern Noise very quickly becomes the dominating noise. If your calibrations frames aren’t good quality then FPN will still be an issue. If you don’t dither sufficiently then FPN will be an issue.
Something else that more frames allows you to do is better sample the accuracy of data. Sometimes when pixel values vary it is due to noise but it can also be due to accuracy. Using the values you had in your first post: 2,3,4,5,6,8
I’d you median it will be 4/5 as it is an even number. If you average all of those you get 4.667. If you average while clipping the high and low values (3,4,5,6) you get 4.5.
Which one of these is correct? The more subs you have the better and more accurate that number becomes. This is where contrast comes in, the accuracy of pixel to pixel variation. With 30 subs it will be more accurate than 1 but with 100 it will be even better!
|