I have long meant to try this favorite in NB. So here it is my go at the Helix in narrowband with the ST2000 and RC10.
It took a few nights to get the data which is 15*24mins Ha and Sii, 8*24mins Oiii. The Sii images were so weak I had to ditch them and blend Ha and Oiii to make a synthetic R. I used the Ha as a L, so this is Ha, Ha/Oiii, Ha, Oiii. Wish I had read OPs first and would not have bothered with Sii....still they say you learn from mistakes not successes so now I must be wiser!
That's excellent
Lots of great detail and some faint bit's I didn't know existed
I made the same mistake when I did it NB, had to ditch about 7 hours of SII.
Ooops - forgot to mention significant info - all the subs were binned 2x2 and I had the APCD667 reducer in line as well! Could not have got the faint stuff in native modes....
Now I look at this image on another PC I can see there is a light band at the top of the image that did not show on my processing machine - I think from a bad dark (light leakage)...I might need to re-do....
Excellent John, I like the colour variation you are showing in the main ring, that's rare to see in Helix images, you have produced a similar colour result to my version here actually
Thanks for all the nice comments, I was very pleased with this result. It is my deepest set of exposures yet - I normally use 10 min subs but post the Ovision upgrade to the G11 I felt I could go longer and not lose frames.
Processing was very much hit and miss with me cycling through various blends for the G frame and weights for the RGBs. I also used some unsharp masking. All the calibrations, stacking and processing was done in AA5.
Mike - the colours I have in my image are inspired by the work of others and the hubble team. When I realised my mistake with the Sii data I went looking for nb Helix images on the web and I tried to get as close as I could to the best of those - and yours is definitely one of the very best so I am chuffed you like it! Actually looking at your image now I see I have made an error in using pure Ha as L - there are details in the Oiii that show in your image that are lost in mine. I might try blending a in some Oiii into the L frame as well, is that how you did it?
Unfortunately I cannot give you a higher res version - as I mentioned the subs were all binned 2x2 so that image is native res for my ST2000 in that mode - 800x600. I did do some unbinned subs but my seeing here really does not justify imaging at < 1" per pixel (Sydney N.Suburbs) and I would have had to go 4 times as long to get the same depth. Perhaps I can do that another time. For now I have done a slight re-process to remove the blue band in the top my image and crop where the frames did not quite align.
