Quote:
Originally Posted by RickS
My experience is that things work in practice pretty much as expected in theory and that higher SNR images look better. Not sure what has happened with your experiment but I wouldn't jump to any conclusions 
Noise is random and hard to estimate accurately unless you have a statistically significant number of samples.
Cheers,
Rick. |
+1 - SNR really is the only measure that matters.
a couple of points:
you have used an averaging stack, which means that the signal will be proportional to the sub length and will not change as you add more subs. However, it will be 5x higher for the 5 min sub. To get a reasonable idea of how much noise you really have, you need to stretch differently so that the signal in each image is the same.
how have you measured SNR? you need a totally flat region to get an SD measure that incorporates just the noise and not some variation in the background level as well. FWIW, the method used in Nebulosity is very reliable.