What order to do processing steps?

Hello all,
I am working on a set of wide-field images around NGC 7000 (North American Nebula)and trying to figure out the correct order for processing steps. I have 3 seperate images that the tracking was good enough to process, each is 10-15 minutes. Not really long enough, but it's what I have. I have been able to tease some detail out of each image individually, but want to stack the 3 together to hopefully pull out more detail and reduce noise.

I assume I should remove the gradiant from each image seperately, before doing anything else. Is it best to next align and stack the "flattened" images before further processing (stretching curves etc.), or is it better to process each image individually and then stack the processed images? Alternatively, do you all think the "raw" images should be stacked prior to removing gradiants and then subtracting out the "final stacked gradiant"?

I am experimenting with different approaches on small scanned images before I scan in at a higher resolution. Finally, what scanner resoultion do you all use on prints or negatives for best results (I am using an Epson 2400 scanner that is 48bit and can can prints or negatives up to 4800dpi optical resolution, but these are HUGE files that are slow to work with).

Sorry for such a long post. Thanks for any and all suggestions.

John

Hi John -

I am by no means an expert, but FWIW I have had much better luck performing all the processing (curves, etc.) after the stack. If you process each image before the stack, all you do is help to bring out the noise in each image.

Also, I believe the gradient should be subtracted out of each individual image prior to the stack.

You might want to ask the question again on the imaging forum where the experts are.

-Jake

Hi John,

As a general rule, always remove gradients etc first, then stack and then process.

Cheers,

Maurice