A bit of the North American Nebula NGC7000.
Slightly odd composition I know, but taken during full moon:-
(http://gallery.orpington-astronomy.org.uk/albums/userpics/10067/NGC70002C_2020-08-07.JPG)
About 17 subs, 600S Ha, Oiii, Sii - do as you like palette.
Stacked and assembled (aligned) in ASTAP, PP in GIMP.
Some odd coloured stars in there, but it adds to the charm I think.
Noel
That's come out well Noel.
Carole
Hi Noel,
I agree with Carole however is this just the red channel for the nebulosity?
Robert
Thanks Carole
HI Robert; no this is all three, but looking at it on another screen it does look very red doesn't it! - Suspect this is partly due to my laptop screen, however, did reprocess it from scratch using SHO instead of HOS with almost exactly the same result. Will try a different screen.
Very good result Noel! It may be my monitor but the black appears a bit clipped to me.
Roberto
Very nice Noel. Lots of contrast and detail.
Join the club on the colours, my astro colours are often iffy once I've uploaded the image. Always looks fine before the forum gets it!
Looks very louring and dramatic Noel!
Hugh
following Roberto's comment about the black being clipped. I checked it in photoshop, it's not clipped but basically the image needs brightening up a bit as there is more nebulosity hidden in there.
Carole
Thanks Hugh and Carole
Duncan; being fairly new to GIMP do you have any good tips / tutorials that might help with colour?
I struggled with PS2, GIMP works better but the blue just gets lost and if I fiddle with the sliders in colour balance it all tends towards grey. The Oiii data was quite good, but nothing to show for it in the image.
Noel
Quote from: NoelC on Aug 12, 2020, 13:02:48
Thanks Hugh and Carole
Duncan; being fairly new to GIMP do you have any good tips / tutorials that might help with colour?
I struggled with PS2, GIMP works better but the blue just gets lost and if I fiddle with the sliders in colour balance it all tends towards grey. The Oiii data was quite good, but nothing to show for it in the image.
Noel
HI Noel,
I hardly ever use GIMP even though its vastly improved. I like DarkTable for final tweaking, really good noise control (filmic is the tool I use), sharpening, local contrast enhancement, contrast adjustment and colour fixing. And it exports to other formats e.g. JPG easliy.
These days I like to stack in ASTAP, let it do the colour adjustment, set the stretch (it does Asinh and btw you can type a number rather than have to use the suggested picklist values), remove gradients (excellent tool even if it seems a bit mickey mouse), bac=sic noise reduction and tweak vignetting correction. I reduce its idea of a good colour saturation level (leery on my monitor) with the tiny teensy slider and export to 32bit TIF then open in DarkTable. I use IrfanView for any final resize/crop and its Save for Web tool means you can adjust how many Mb's the final image for upload will be.
HTH
Duncan
Oh, and I look up the subject on the web for other peoples idea of what an object should look like :)