M22

[gonzostar]

Hi

First saw this great globular cluster in Portugal many years ago. So hopefully done it some justice

managed to collect a image of the M22

12 * 2 MIN lights (unguided), with darks, bias 

DSS then gimp

8" SCT (with 6.3 focal reducer) on a AVX

450D Canon camera

Any feedback on improvements welcome. Or please feel free to improve this image

Thanks for looking

Dean

[ollypenrice]

I think the image deserves a significant adjustment to the colour balance, which is massively slewed towards green. The entire starfield and background sky in this region is on the red side due to the older stars in the galactic centre and the redenning effect of the dust. This ought to be quite easy to do. My first step would be to align the top left of the histogram peak in each channel.

https://ollypenrice.smugmug.com/Other/Takahashi-EM200TEC140/i-F86wcdt/A

You can do this by bringing in the black point (lower left slider in Levels) on any peak which needs to move to the left.

Olly

[gonzostar]

Thanks Olly for your link and advice. Are you alligning the top left of each peak in DSS or processing software? (at moment using gimp)  

or align in gimp then use levels to match the data on histogram?

Cheers

Dean

[ollypenrice]

I'd do it in Gimp I guess. I use Photoshop, but Gimp has levels and curves, does it? Assuming so, give the linear a stretch, adjust the top left of the peak, give a further stretch, etc.

Olly

[gonzostar]

ok will practice