What order to do processing steps?

Started by jactheo, 06/25/2003 03:11PM
Posted 06/25/2003 03:11PM Opening Post
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

John Theodossy
http://geocities.com/myastrostuff/
Posted 06/25/2003 03:50PM #1
John,
You should always stack the raw images first to pick up the most detail. If you process before, you may actually remove some valuable data that is hard to see in the individule image.
Hope this helps,
Don Spencer

Don Spencer
http://members.cox.net/ecdon/astrophotography.html