I sent my d70 to the Nikon Hospital yesterday for a final warranty tune-up, so I'll have a few weeks to edit photos... something I enjoy almost as much as taking them. I do a lot of selective adjustments using layer masks, which sounds more difficult than it is. But it was a concept that was difficult for me to grasp, so I thought I'd take a stab at explaining it for new photo-finishers.

Here's a photo of mother and child that needs adjustment to better display their beauty.

http://www.pbase.com/unclefrank/image/40846449.jpg

A global levels adjustment, will work, but also brightens the background, which I'd rather avoid.

http://www.pbase.com/unclefrank/image/40846450.jpg

One way around this is to create a duplicate layer [press ctrl + J], apply the global levels adjustment to the upper layer, and then use an eraser to remove the parts of the top layer that didn't need brightening.

http://www.pbase.com/unclefrank/image/40846451.jpg

The problem with this approach is, should you find you made an error, you might have to go back to the beginning and start all over again. Fortunately, Photoshop offers a more forgiving and elegant solution... layer masking.

After you've created the duplicate layer and globally adjusted the levels, go to [layer - layer mask - hide all]. You'll see that a black square has been added to the icon for the top layer, and that the levels adjustment you made has been hidden.

http://www.pbase.com/unclefrank/image/40846452.jpg

Now set the foreground color to white, click on the black mask icon, and select the paintbrush tool. Wherever you paint on your picture, you'll change the mask covering that portion of the image to white, letting the levels adjustment show through.

http://www.pbase.com/unclefrank/image/40846453.jpg

Oops! Now you see why I got a low grade in coloring in kindergarden.... I can't paint between the lines :?. Those lighter colored blobs on the background are where I screwed up and painted white on parts of mask that should have been left black. No problem! I'll just change the foreground color to black, and carefully paint back in black on those portions of the mask.

http://www.pbase.com/unclefrank/image/40846454.jpg

This masking approach works on any change you'd like to make to the upper layer, including levels, sharpening, hue/saturation, etc. For example, the amount of sharpness of this picture works well for the child, but isn't very flattering to the mother's mature skin, so I created a duplicate layer, and applied 1 pixel of gaussian blur to the picture. Then I used a hide-all layer mask, and painted white on the mask over areas where "character lines" needed to be softened, leaving the rest of the image sharp.

http://www.pbase.com/unclefrank/image/40846455.jpg

I can guarantee you that once you understand the concept, you'll find countless uses for layer masking.

Feel free to download the original image and work through the steps I've outlined. If you run into any problems, I'll be happy to explain the process in more detail.

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Warm regards, Uncle Frank
FCAS Charter Member, Hummingbird Hunter, Egret Stalker
Dilettante Appassionato
Gallery at www.pbase.com/unclefrank/nikon