Veil Nebula: First Effort

[feilimb]

Hi all, I dusted off the ASI294MC Pro last week and on a clear night with a 90%+ moon I captured 36x5min exposures of the Veil Nebula, with Skywatcher ED80 and 0.85x focal reducer and an Astronomik HA filter (which may be slightly dodgy).  I also captured 30 darks which were used in calibration. I tried capturing flats and dark flats but I still cannot crack the dark arts of flats, and when I use them in a stack I get a horrible ring around the centre of the image from some kind of over correction.

My image processing skills are not great so perhaps someone else would like to have a try with the data too (stacked with DSS). Any pointers greatly appreciated, there is still a lot of noise in the stacked image I had hoped there would be less with the number of lights and darks obtained?

Note #1: I extracted the RGB channels, then used LinearFit with the red channel as reference, and then recombined with LRGB combination for a basic colour calibration.

Note #2: I'm pretty sure the halos around the stars are induced by the filter. I have seen the same halos effect when using the same filter on different targets (it is a filter I got for free from a kind fellow forum member just to get me started with HA captures, but he noted that there may have been some issue with the filter).

 

Veil_LightsDarksOnly.TIF

Edited September 23, 2019 by feilimb

[Stuf1978]

Hi, 

I had a bit of a play around with your data as I don't need any excuse to practice processing as I'm still rather crap at it. There is plenty of detail in your tif file but I couldn't seem to get shot of the halos around the stars. So you may be right about the filter. 

Stu