Unbelievable Madagascar September 14–October 1, 2007
				India Wildlife: On the Trail of the Tiger November 7–24, 2007
				Angkor Wat & Bagan—Temples of Cambodia and Myanmar January 17–31, 2008

After wrestling for a while with the beast that is Photoshop, most people find a technique that works for them. While the program offers myriad ways to accomplish most tasks, we become expert in only a few from that vast toolbox. My go-to tool is the Layer Mask.

With this simple tool, you can make selections and blend images together without bothering with lassos, magic wands, marquees, or the damnable (but powerful!) pen tool. You may apply a filter, add and adjust the opacity of a gradient, or combine two or more pictures together. A Layer Mask allows for infinite do-overs without affecting the underlying image.

I often use Layer Masks to combine exposures. If I know that the contrast in a scene exceeds the range of the camera’s sensor, I take two or more exposures and over the bad exposure to reveal the good.

When I fail to take different exposures in a high contrast situation, I open the file in RAW and convert it to a Photoshop file. Then, I open the same picture in RAW again and change the exposure to optimize areas that were over- or underexposed in the original.

After converting the second version to a Photoshop file, I drag one image over the other by holding down the V key as I drag. Holding down Shift at the same time aligns the two images perfectly. Then, I add a Layer Mask to the top layer by clicking on the circle inside a square at the bottom of the Layers Palette or by selecting Layer Mask from the Layers menu.

I pick a brush from the Tool Palette and select the size, hardness (i.e. the fuzziness of its edges) and opacity. With a lower opacity I can slowly add to the strength of the effect and create undetectable transitions between layers. Click on the empty canvas, the Layer Mask, next to the tiny thumbnail of the top layer. This activates the Layer Mask.

Notice two squares, one black and one white, among the tools. A small curved arrow acts as a toggle, or you can press X to switch back and forth. When the white square is active, the brush will reveal the underlying image. When the black square is active, the brush will conceal it. White reveals, black conceals.

In the image of a bridge in Shanghai, I followed these steps and then painted out the underexposed buildings, revealing the correct exposure in the lower layer. I used 50% opacity for nice transitions and could have gone to 20 or lower. When I was happy with the result, I flattened the image and saved it with a new name.

Once you learn the steps, you can open the images, open the mask, and apply the correction in a matter of minutes.

Try playing with Layer Masks—a non-destructive way to work on images.

Be sure to check out James' latest book, DIGITAL PHOTOGRAPHY OUTDOORS: A Field Guide for Adventure & Travel Photographers, published by The Mountaineers Press.

All images Copyright © James Martin