Thursday

Masking local adjustments in Lightroom 2

The localized adjustments pane in Adobe Photoshop Lightroom 2.2 has a nice little feature that I didn't pay much attention to at first, but now I use pretty frequently. When you are using the Adjustments Brush in the Develop Module you can view the area that you're brushing by means of a mask that Lightroom creates.

Use the "K" key or click on the brush icon to call up the local adjustments brush.

You can do this either by having the mask turned on while you're painting, or you can use the "O" key (for "Overlay" I suppose: not zero) to toggle the mask on and off to show where you've painted and where you haven't. This is very useful if you are trying to just apply an adjustment to a specific area and don't want the nearby areas to be affected.

Even more useful, you can change the color of the mask, which is something I really love.


The green area shows where I have painted with the adjustment brush.

A few years back I got very comfortable with the QuickMask feature on Photoshop, but I found the the default reddish-orange color of the mask was hard to work with because it is sometimes fairly close to the skin tones of people in my pictures. In the sunset photo above I've got a lot of red going on in the photo in and around their faces, and a red mask might make it hard to tell where I'm working.

In Photoshop you can change the color of the mask using the color picker, so in that program I went in and changed it to the brightest fluorescent neon green I could find, which is a color that hardly ever shows up in real life in my pictures. If I were primarily shooting in the rain forest, I might pick some other color, but this suits me fine.

Lightroom offers 4 different options for mask colors. (No pun intended.)

In Lightroom, the default mask color is red, which isn't quite as subtle as the default QuickMask color in Photoshop but still gets in the way from time to time. If you use the "SHIFT-O" keyboard shortcut, you can cycle through two or three other options for the colors, and it turns out that one of them is my good old fluorescent neon green. The other colors are white, and black, but each of those gives the appearance of being a screen and I don't find them as useful for my needs.

Usually when I'm painting in an adjustment, I don't start with the mask showing, because I like to see how the effect looks as it's being applied (and not just see where it's being applied.) That way I can adjust my brush flow or the strength of the effect if it starts out being too much or too little. Then, to check that I've got the effect applied every where I want it and excluded from everywhere I don't, I press the "O" key and the mask pops on to indicate where I've worked.

One thing I should point out is that you don't have to actually apply an effect to an area to make the mask. That is, you could have all the brush options set to zero (or their middle points on the sliders) and paint the mask, and then apply the effect after by moving the sliders. But normally I have some idea of what I want to do, and how much of it, so it's rare that I would just make the mask. But if you want to paint it first to see that you're going to apply the effect exactly where you want it, you can.

If I've overpainted, then the magical and wonderful Option key comes in to play (Alt on a PC). By pressing it down, the little plus sign over your brush circle becomes a minus sign, and you can erase your mistakes. If you need, you can change your brush size, feather or flow while you're erasing, but you need to keep holding down the Option key while you're doing this.

Because I have this much control, it's fairly uncommon that I ever need to use the "Auto Mask" feature, which you can turn on with the little checkbox. This feature, I think, is named poorly because Lightroom is always creating a mask for you. It might be better to think of this as the "auto apply" or "auto zone" button.

With Auto Mask checked Lightroom tries to be smart enough to paint just where you want.

The Auto Mask feature is supposed to automatically apply the adjustment where you want it, and not apply it where you don't. It does this based on the color in the image directly under the little "+" sign in the brush circle. This works great when you have, say, the edge of a building or the petal of a flower that you want to adjust, but with the subtle gradations in most people's skin tones I find that it leaves a kind of choppy effect that is not what I'm looking for. So I generally leave Auto Mask unchecked and just adjust the flow of my brush as needed with the number keys on my keyboard. Press "0" (this time it IS zero) for 100% flow, or "6" for 60% flow, "3" for 30%, and so on. If you press two keys quickly, like "68," you get 68% flow.

In areas where the colors are similar to what you're painting, Auto Mask sometimes has trouble
hitting the mark and can spill over in to neighboring areas where you don't want to apply the
adjustment. Here, it's easier to use the Option key to undo the painting than to try Auto Mask.


As you can tell, I'm a big fan of using my keyboard to make quick changes in the settings and dialog boxes in Lightroom. If you'd like a complete list of them, you can find a downloadable PDF at Rick Miller's Adobe Education Technologies blog. Very useful to have as a quick reference.

For all of these examples I've overdone the painting and correction to show the effect of the mask and its options. My apologies to my humble subjects, who really do look better than I've shown them here.

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