More frames in the stack, the better the SNR.
It really depends on the possible movements (within the target) across the total amount of frames.
Consider a solar prominence.....how much internal movement across 2000 frames vs say 500.
The quality measure is based on the quality of the total frame count- you could have good quality at frame 100 and frame 900 but with different image content.
That's the compromise. I now do my solar in 500 frame videos to minimise the effect.
|