Omega Cen by moonlight.

[tilbrook@rbe.ne (Justin Tilbrook)]

Hi,
Another moonlight image, Omega Cen this time and again a cropped image. I've been playing around in Photoshop trying to get the star colours right. Some images of omega I've seen on this forum have a distinctly golden hue to them, so thats what I aimed for.
It does seem to screw around with the background when using saturation for the stars, any tips?
Equipement.
8" f/4 astrograph.
HEQ pro 5 mount.
Camera Canon 1100D, no coma corrector at ISO 200.
20 x 60 subs.
9 darks, 9 flats, 9 bias.
Stacked in DSS and processed in Photoshop.
Cheers,
Justin.

[Ross G]

Hi Justin.


A very good photo. Sharp and lots of detail.


Ross.

[White Rabbit]

Nice shot, try boosting the saturation a bit to make the older stars pop out.

[jjjnettie (Jeanette)]

On my monitor the background is very blue, caused by the moon of course, and it looks a tad over sharpened (there are dark halos around the brighter stars ).
That said though, you've got a nice image.

[Rigel003 (Graeme)]

Nice image, Justin. The balance does look too blue on my monitor too. If you want to adjust star saturation without changing the background you need to select the stars separately and then operate on them only. Try Select - Colour Range - highlights. This will get the brightest stars (or you can do Colour Range - Sampled colours - click the eyedropper on the stars and adjust the degree of fuzziness to get more or less stars). At this point you can optionally feather the selection so there's not an abrupt transition between the selected and non selected areas. (Select - modify - expand by 4 pixels, feather by 2 pixels).

To increase saturation I'd suggest (Image - Adjustments - Match Colour - Intensity) rather than the saturation slider. After that you can invert your selection (Select - inverse) giving you the background sky, and adjust the colour balance to reduce the blue, or desaturate it a little.

[tilbrook@rbe.ne (Justin Tilbrook)]

Thanks for the comments and tips.
I'm slowly learning the processes required, one at a time.

After all I'm a male, can only handle one thing at a time!

Cheers,

Justin.

[tilbrook@rbe.ne (Justin Tilbrook)]

Hi,

Did a bit more processing, with the advice given. I managed to get more of the blue out. I'll image omega again without the moon shine, it will be interesting to see the difference.

Cheers,
Justin.

[alistairsam]

Hi Justin
In my monitor and the iPad, the first one looks Better even with the blue hue
Maybe adjust hue for mid tones and highlights but not shadows or just mid and shadows
The eye dropper tool is an accurate way of measuring color as it will show you the rgb percentage as you move it across and that's independent of monitor calibration

Interesting to see slight coma in three corners out of the 4.
Did you sort out the spacing, it's getting better though
Look forward to more
Cheers