|
Great wisps of nebulosity on display Adam. Very nice work. Be careful with only selecting the nebulosity and not the stars when selectively processing data. It important to try keep the image aesthetic. Bright nebulosity without vibrant stars can look out of place.
You can use the basic colour range tool in PS, feather and inverse the selection. This may however only pick up the brighter stars. If you want to select even the fainter stars you can do the following;
Star Selection (from Russ Croman):
1. Make a grayscale copy of the image. I'll call this image #2.
2. High-pass filter image #2 with a radius of one pixel.
3. Apply a Gaussian blur to image #2 with a radius of one pixel.
4. Invoke Image->Adjust->Threshold.
5. Adjust the Threshold Level one click at a time until just the stars are white and everything else is black.
6. In the original image, in the Channels Palette, create a new channel. Name it "Stars." Choose "color indicates masked areas."
7. Paste image #2 into this channel.
8. Make just the RGB channels visible (i.e. make the Stars channel invisible).
9. Discard image #2.
10. In the original image, invoke Select->Load Selection. Choose the Stars channel you just created.
11. Invoke Select->Expand and expand the selection by a few pixels (e.g., three).
12. Voila!
|