A new way to star mask?

[ollypenrice]

Well, new to me. You may already have thought of this years ago!

1) Take linear image and stretch slightly to expand the stars a little.

2) Black clip it till all (or nearly all) nebulosity is removed, leaving only stars.

3) Gaussian blur (trial and error. Try 1.5 to start with.)

4) Ctrl I to convert to negative.

5)Set aside for a sec.

6) Open linear image.

7) Copy layer and create blank layer mask.

8) Paste negative image from 5 above onto layer mask.

9) Make linear image active and stretch as usual, watching for the appearance of artefacts on the stars. When they appear flatten the layers and carry on without star mask.

This differs from the net tutorials I've seen in using a slightly stretched image to make the star mask. It gave me a mask which produced more natural stars and it lasted for a couple of stretches instead of just one. I also think its easier to clip and observe the mask before converting it to negative.

Olly