Ok, we've shamelessly copied Strong Mike here. Last night we added 9 hours of 2x2 binned H-alpha to our previous 28 hours of 1x1 luminance and 4 hours per channel of 1x1 RGB.
The result (big one here) is once again pleasingly similar to Mike's. Pleasing in the sense that if you are doing science or something like it, and you do the same experiment, you should get the much same answer.
The H-alpha (mapped to red, and just averaged with the wideband red) produced a transformation: big swirly clouds of nebulosity against an otherwise somewhat featureless galaxy. It is still very disrupted compared with what you can see in Barnard's Galaxy or NGC 300 in H-alpha.
Oh, for the colourblind, swap the red and green channels in PhotoShop, or you won't see anything different from before.
Best,
Mike and Trish
Edit: After some discussion, we've increased the relative amount of red. The hyperlink now points to the revised version. The left hand thumb is "before" and the right hand thumb is "after".
Nice one guys. I did this one a few years ago with a different camera. I'm tempted to do it again now.
Cheers
Steve
Thanks, Steve. Glad we've inspired you.
Quote:
Originally Posted by markas
It's a great image Tremendous detail!
One little niggle - on my colour calibrated screen, the body of the galaxy looks a bit greenish....
Mark
A very good observation Mark. I think what happened was the original without H-alpha was relatively well balanced, but because the H-alpha was more topographically discrete, when I averaged the two, the net result was less red, particularly in the areas without special nebulosity. I've reprocessed it under Trish's watchful gaze, stopping short of burning out the H-alpha in an attempt to get the colour balance right. Not as easy as I imagined! The hyperlink should now point to the new, improved colour balance. I've left the old thumbnail. The thumbnail immediately below shows the new colour balance.
Quote:
Originally Posted by Atmos
Just getting better and better
It is subtle but an improvement.
Thanks muchly Colin.
Quote:
Originally Posted by peter_4059
The Ha certainly makes this galaxy look more appealing. Interesting to see the bright core also.
Definitely worth the extra time to add in the Ha MnT
Thanks Rodney! So now we've done several galaxies that look good in H-alpha. From easiest to most difficult, it might be something like:
NGC 300 (amazing and easy to understand what you're looking at because it's face-on)
Barnard's Galaxy (amazing but smaller and fainter)
NGC 55 (easy but harder to see what you're looking at because edge on and tidally disrupted)
Sculptor semi-dwarf (small and faint but you can just make out a micro-quasar !)
Hamburger, where with very long exposures you see the huge faint relativistic jet arching far from the galaxy.
Nice work, M&T. I like the added zing a lot 
