The Value Of Brightness/Contrast

How a much maligned adjustment tool can help you work images like a darkroom master
The Value Of Brightness/Contrast

As soon as I mention the Brightness/Contrast adjustment control, I know some Photoshop sophisticates will turn up their noses and figure that I’ve lost it. Brightness/Contrast is the adjustment control that the experts love to hate and denigrate. Yet it has powers that are perfect for anyone interested in going beyond basic Photoshop adjustments.

I once told a friend who’s a well-known Photoshop expert that I was using Brightness/Contrast for some special purposes. He sat down and determinedly worked at the computer, trying to find an alternative because, of course, everyone knew Brightness/Contrast was a lousy control only used by rank amateurs. He just couldn’t permit me to go down that path of darkness. But I did. And Brightness/Contrast did what I needed to be done better than anything he could come up with.

Let me first tell you when I don’t use Brightness/Contrast. I never use it for overall adjustments of an image. The problem is that Brightness/Contrast is a rather blunt instrument. Using it for overall adjustments is like trying to sculpt detail in a statue with a sledgehammer. You may get the groove you wanted, but you’ll get a lot more happening that you don’t want.

So for overall adjustments, you start with Levels to adjust the blacks and whites, then Curves for midtones (see Digital Horizons, August 2006 for more details). These controls offer the ability to adjust one thing without affecting everything else in the same way. Brightness/Contrast doesn’t work that way. It makes everything brighter or darker, everything more or less contrasty. That rarely makes an image look its best.

When exactly is Brightness/Contrast best employed? I use it to give me the control I used to have in the darkroom, a control that I always used for black-and-white work, then I rediscovered its benefits in Photoshop for any image, black-and-white or color. This is burning in specific areas of a photo to darken them to bring out the best in an image.

The term "burning in" comes from the darkroom. A darkroom master would "burn in" areas of a print by adding more light in highly restricted ways while exposing the print under the enlarger. Ansel Adams was a master of this. If you read books about his technique, especially The Print (still in print), you’ll discover he did a lot of darkening along the edges of images, then darkened other parts of a photo as needed. He’d also dodge (block the light) to lighten areas, but I don’t find Brightness/Contrast works for that (I use Curves).

The great photojournalist W. Eugene Smith was another master of the darkroom and loved to burn in specific areas of an image to ensure the final print matched his vision of the scene. In fact, most photojournalists burned in the edges of images, at least, because it helped keep the eyes of the viewer on the subject.

The reason for all this burning in is simple. Photography records the world much flatter than we see it. Of course, part of that has to do with a two-dimensional medium, but it also has to do with how a camera sees the world compared to our eyes. Imagine a landscape with a flowering tree in front of a large scene. We see the tree as dominant in our field of vision, with everything else less sharply seen and definitely subordinate to what we’ve focused on.


The camera, on the other hand, sees everything with a flat point of view—everything in that light and focus is equal across the image area. The tree has none of that special focus, which is our way of seeing the world.

Brightness/Contrast on an adjustment layer is perfect for darkening things because it does exactly what the darkroom burning used to do—it darkens everything equally. So by controlling where that darkening occurs, I can somewhat control how a viewer looks at my composition and my subject. The steps are simple:

1. Open a Brightness/Contrast adjustment layer. I like to use the adjustment layer icon at the bottom of the Layers palette.

2. Darken the whole photo about 20 points. I use 20 as an arbitrary value to help me see some effect; I change the adjustment layer’s controls later at no cost to the quality of the image.

3. Fill the layer mask of this adjustment layer with black (Edit > Fill > Use Black). This turns off or blocks the effect of the layer (remember, black blocks).

4. Using a large, soft brush, use white to paint in the effect of the layer (white permits the effect) in places that need darkening. The layer mask doesn’t affect the photo; it can only control the layer it’s attached to. So adding black blocks that layer while white permits or reveals the effect. In this case, white permits the darkening, black blocks it.

5. Paint in things like the corners and edges of a frame, plus any bright areas that seem to be out of balance with the rest of the photo. You can always get rid of anything you don't like by filling the layer mask again with black or by deleting the adjustment layer.

6. Readjust the control by opening up the dialog box for Brightness/Contrast (double-click on the adjustment layer icon on the layer in the Layer palette) and changing the amount of darkening. You can also use the layer’s opacity control to lighten the effect. Advanced techniques include reapplying a Curves layer to lighten midtones overall and using the Gradient tool for blending the layer mask black and white.

I don’t try to use Brightness/Contrast for blown-out whites. Washed-out white areas aren’t corrected easily with any technique, and the best thing here is to avoid it when you take the picture in the first place. This technique can come to the rescue when shooting in flatter light conditions, though its application is a bit different:

1. Create a selection around your subject or a key part of your composition, then invert that selection (Select > Inverse). You want to control the outer part of the image.

2. Add a Brightness/Contrast adjustment layer and make a very strong Brightness change, maybe darkening by 40 points or more. The selection created a layer mask with black and white already applied, but right now the edge is way too hard.

3. Use Gaussian Blur to blend the edge between the black and the white in the layer mask. Try something really high, even pushing the slider all the way to the right. You’ll be amazed by the effect.

4. Tweak the layer mask as needed by painting in (white) or out (black) the effect with a large, soft brush.

5. Tweak the darkening effect by changing the amount of the Brightness slider or the opacity of the layer.

 

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