If digital cameras had the exposure latitude of the human eye, it would be downright miraculous. Part of the art and science of photography is accounting for the fact that cameras have only about half the range. So something that looks breathtaking in person often looks under- or overexposed when captured by a camera.
There are some fancy technological workarounds to this problem. Ulead PhotoImpact 12, for example, has a "high dynamic range" feature that lets you combine several pictures of the same scene, taken with different exposures, to automatically achieve a photo that pops with highs, lows, and everything in between.
This week, though, let's see how to improve photos that suffer from exposure problems, using just your favorite editing program. As usual, I'll use Corel's Paint Shop Pro, and you can apply this technique to almost any program.
Don't adjust the whole photo
Sometimes you don't want to apply an exposure correction to the entire image. Take this photo, for example.
You might be tempted to fix the image by using the histogram to lighten the parts of the image that are in shadow--and that is a quick-and-dirty way to go. In Paint Shop Pro, choose Adjust, Brightness and Contrast, Histogram Adjustment. You should see a histogram graph that's heavily weighted to the left, which means the image has a lot of dark pixels, and few bright ones.
To brighten the image, drag the white triangle that's on the far right under the histogram towards the left until the number in the box at bottom right is at about 15.000.
That's better in some ways. Notice how we've restored a lot of detail to the shadows. But we also overexposed the sky in the process, making the clouds so bright they almost hurt the eyes. There's a better way. Click Edit, Undo and let's try again.