StarTools

So dithering turned out to be very helpful in solving the issues I was having with the pattern noise. However, I'm having some weird gradient issues processing in Startools so I thought I would post to see if anyone had ideas on what could be causing the issue. I tried to increase precision in wipe.

My first processing attempt.

http://www.astrobin.com/156680/

Raw file for download
http://1drv.ms/1CwBusP

I would suggest you need longer exposures to get a better s/n ratio. 210sec is really not much for nebulae and you're going to be working right down there on the noise threshold. Try 10mins and see what happens.

ChrisH

I usually go 5 min (my sky washes out at 6min to 7min) but I happened to have all the dark files for 3.5 min so I went with that. Keep in mind this is a hyperstar at F2.

midwayexpress wrote:I usually go 5 min (my sky washes out at 6min to 7min) but I happened to have all the dark files for 3.5 min so I went with that. Keep in mind this is a hyperstar at F2.

OK, but I did download and run through processing your data, comparing results I think you did a good job and probably got all there was to be had from it. The weird gradient background is just the noise floor (I think).

ChrisH

midway - I had a look at your image as well and the data appears to be truncated. Stretching is near impossible. So you have done a pretty good job getting what you have. If your individual subs are OK, this is most likely a calibration issue. Are you using a DSLR?

rowland

Just saw this right now. No I'm using an Atik 420c and then DSS to stack.

On second thoughts, I have seen this with an SBIG and never resolved the issue.