by Dave Johnson, PCWorld   Jul 23, 2012 6:30 pm

Cameras are, like Spinal Tap’s Nigel Tufnel, easily confused. If you take a photo of a scene that has a lot of contrasty lighting, you’re likely going to end up with parts of the photo that are under- or overexposed.

I’ve got a trick that takes less than two minutes and is perfect for situations in which you want to take a photo with badly underexposed areas and make it presentable for uploading to Facebook. It won’t be perfect, and I wouldn’t use this approach to make a large print, but it’s awesome for rapidly making snapshots presentable.

Duplicate the photo

There will be two copies of the photo in the Layers palette.

You can do this in almost any program that supports layers; I’ll demonstrate it using Adobe Photoshop Elements. Suppose you have a photo like the Before example at the bottom of the story, in which a strong backlight casts important parts of your subject in shadow. Open the photo in your editing program and duplicate the photo in a new layer. In Photoshop Elements, do that by choosing Layer -> Duplicate Layer and clicking OK. You’ll now see two copies of the photo in the Layers palette on the right side of the screen.

Open the photo in your editing program and duplicate the photo in a new layer.

Invert the layer

Next, we want to work with the top layer a little. Make sure that the top layer is selected in the Layer palette, and then choose Enhance -> Adjust Color -> Adjust Hue/Saturation. Grab the Saturation slider and reduce it by 50 percent so the slider says -50, then click OK.

Adjust the colors in the layer.

Now for the fancy bit: With the top layer still selected, press Cmd-I, which will invert the colors in the layer. The top layer should now look sort of like a photographic negative. It might not look like it, but we’re one step from being done. In the Layers palette, change the mode from Normal to Overlay.

Instantly, you should see a much better photo. It’s not perfect, and you could likely do better if you had a half hour to spend with some more advanced exposure correction techniques. But compare the new photo to the original: The shadows are much improved, making the image quite usable.

To finish the photo, control-click (or right-click) on the Layers palette and choose Flatten Image.

Now you can run a little noise reduction on the image (select Filter -> Noise -> Reduce Noise), which might be helpful if brightening the shadows brought out a lot of speckling. Save the image. That’s it.

Before

After

Editor’s Note: The  article is reprinted from MACWorld.com.