Masked stretching is easier than ever...

[ollypenrice]

An update on a form of Photoshop masked stretching I posted a few years ago. This assumes you have done two things first, to the linear image.

1) Given it a reasonable stretch in Levels. I stretch until the stars are about the size I'd like to see them in the final image, or maybe a little bit bigger. This will not be a full stretch, therefore.

2) Removed the stars. I use StarXterminator but Starnet is an alternative.

At this point, using a masked stretch is now a breeze because you won't be stretching the stars.

- Create copy layer and add a Layer Mask.

- Copy the image onto the layer mask.

- Equalize the layer mask. (Image-Adjustments-Equalize.) This gives a kind of hyper-exaggerated stretch with radical extremes of contrast - just what we want.  We must now use some judgement in looking at the equalized mask, remembering that white is transparent and black opaque with grey in between. When we stretch the top layer a little more, the stretch won't be applied under the blacker parts of the mask and will be applied under the whiter parts. You can use the contrast tool or 'Edit-Fade Equalize' to adjust the extremity of the mask's contrasts.  It is also vital to give it a big Gaussian blur, probably 3 or 4.

- Stretch the top layer gently and watch the faint stuff rise out of the background.

So simple.

Olly