Sorry if this has been covered before. I'm new here and didn't find anything when I did my search. My question is:
I have 16 exposures at 15 minutes each. I determined (after taking them) that it would be better to have longer exposures. So I took 10 exposures at 30 minutes each.
Now my question is, what is the best way to combine them? Should I process the 15 and 30 minute exposures separately, stack them separately, and then use pixel math to combine the results? Or can I stack them all somehow to come up with a better result? You might have guessed that I am working with narrow band images and I found that my SII and OIII images were a bit grainy (not sure what the correct term is here) when I did my original combination of the 16 exposures of 15 minutes each. Hoping that 30 minute exposures will reduce the noise.
I'm not great with Pixel Math, so if this is the best route, what is the correct equation to combine the 2 stacked images (the result of stacking the 15 minute images with the result of stacking the 30 minute images)
Suggestions would be much appreciated. Basically I'm looking for a way to combine images so that the original 4 hours of exposures can be combined with the new 5 hours of exposures to get the best results.
