When Bad Photographs Happen To Good People

We've all had it happen-a once-in-a-lifetime shot is ruined by bad exposure, red eye from an on-camera flash, a totally distracting background object, or bad color balance. Maybe you can't go back and reshoot, but with digital images, chances are excellent that you don't have to pitch the image into the recycle bin either.

With basic image-editing tools, you can usually salvage the image, or at least apply a creative effect filter and get an image you might not otherwise have gotten. Most photo-editing programs on the Web or on CD-ROM offer a variety of image-editing tools that allow you to make basic adjustments such as cropping and fixing red eye. But if you're new to working with digital images, it's difficult to know where to begin. Using the most basic editing tools, even beginners can make modest to dramatic overall improvements in images.

Before you begin, there are two important cautions:

• Always make a copy of the original picture, and then work on the copy. Keep your original images in a separate folder. This ensures that you can start over with the pristine - or not so pristine - original if you don't like the changes you make.
• Verify that the software you're using provides an option to undo each change. The ability to undo each change becomes more important as the amount of time you spend editing the image increases. If all the previous changes you made were great, but the last one is totally unacceptable, then you want to be able to undo the last change and not lose your previous work.

The following is a rundown of basic image-editing techniques and potential trouble spots to avoid.

When to use this technique  Cropping is effective when you want to:

• Eliminate unwanted or distracting background objects.
• Make the image fit within a prescribed size, such as the dimensions of the paper on which the image will be printed, or the dimensions at which it will be displayed on a computer screen.
• Improve overall composition by focusing more specifically on the subject. Cropping brings the viewer's focus immediately to the subject and eliminates the extraneous room clutter.

What can go wrong?  Cropping can go wrong if you crop out the wrong parts. For example, it isn't good if you crop out a person's arm or other vital elements of the subject or overall image.

Also, if you plan to have the image printed by a commercial photo printer, crop the image in proportion to the size of paper (8 by 10 inches, 5 by 7 inches, etc.) on which it will be printed. If you crop the image to a nonproportional size, the image must be stretched to print edge to edge.

For example, if you crop an image so that it is square, and then you order a 5-by-7-inch print, the resulting photo will be stretched to fit the 7-inch dimension, and, in the process, some image area along the shorter dimension may be cropped as well. But the biggest downside to stretching or enlarging the image is the inherent loss in image sharpness.

Some image-editing programs such as Microsoft Picture It! give you the option of maintaining proportions when you set the image print size. If you're using a Web-based program, check to see if it offers a preview of the print at the size you chose. The preview will show if additional cropping is necessary to make the image fit the size you specified.

When to use this technique  When the eyes of subjects in your images appear disconcertingly red, it's time to use the red-eye fix option. Red eye happens when you photograph people or animals in dim light using an on-camera (or pop-up) flash. In dim light, pupils become dilated. When the camera flash fires, the light goes directly into the subject's dilated pupils, and then bounces off the back of the eyes so that the eyes subsequently appear red in the image.

Some newer cameras try to reduce red eye by firing a pre-flash to contract the subject's pupils before the main flash fires. While the results vary by camera, it's worth using the red-eye reduction option when you photograph using the on-camera flash.

Even if you forget to turn on the red-eye reduction option, most image-editing software makes it easy to fix red eye. For example, in Picture It! Photo, it's a matter of zooming and clicking each eye to return the subject's pupils to a more natural color.

What can go wrong?  Virtually nothing. Just follow the directions and fixing red eye should be quick.

When to use this technique  When an image has a yellow or green tint, you will want to correct the tint to more natural overall colors. A yellow tint results when you photograph using daylight film under ordinary household (tungsten) light without using a bluish (80B) filter. A yellow tint also happens if you forget to adjust the white balance on a digital camera for the light you're photographing in.

A blue cast results when you photograph using daylight film under fluorescent lights without using a magenta (FLD) filter. Or, when you forget to set the white balance for the light you're photographing with on a digital camera, your image will have a blue cast.

Tint correction tools vary by image-editing program, but it's a good idea to start by trying the automatic fix option. Typically this option finds the lightest point in the picture and makes it white. It may also adjust the brightness and the contrast (the degree of difference between the lightest and darkest parts of an image).

If you're not satisfied with the automatic fix, undo the changes, and then set the white point. The white point tool is often represented by an eyedropper. Using the eyedropper, you click a point in the picture that should be white. The image-editing software uses the point you click as a reference for what should be white, and then adjusts the rest of the picture automatically.

If you're still not happy with the tint, undo the previous changes, and adjust the tint manually. This should be a last resort because you can spend a lot of time making adjustments that result in little more gain than you would get using the automatic fix option.

What can go wrong?  Using either automatic or manual tint correct can shift the color too far in one direction or another. While you may be able to get the photo to an acceptable tint, the process can take considerable time.

When to use this technique  When an image is too light or too dark overall, you'll want to correct the exposure. A correctly exposed photograph should display a full range of tonal values (light, middle, and dark tones). Normally, your camera's built-in metering system takes care of exposure automatically. But some scenes can fool a camera's metering system. Most camera metering systems are calibrated to give correct exposure when the scene being photographed reflects an average of 18 percent of the light falling on it. In oversimplified terms, the camera expects the overall reflected light to average out to a mid-gray tone.

With this in mind, you can now understand why when you photograph a snow-covered mountain, you get images with gray snow. The camera metering system automatically tries to average the white snow down to gray, resulting in an underexposed image. Likewise, if you focus on a small white boat isolated on dark blue water, the dark blue reflects little light and the camera's metering system also attempts to record it as gray. This results in overexposure. You can use exposure compensation, if your camera offers that option, or you can manually set the exposure to compensate for these types of scenes.

But whether or not your camera allows you to manually change the f/stop as you photograph, you can almost always improve a poorly exposed image on the computer. For example, in Picture It! you can correct detail rendition at the same time you adjust brightness and contrast, or you can use the auto-fix option.

What can go wrong?  With auto-fix options, you can go from dramatic improvement to images that are worse than before you started. And this is why the ability to undo changes is important. Start by using the auto-fix option or options. If you're not satisfied, most programs allow you to tweak settings individually.

On severely overexposed or underexposed images, you may be doing well if you achieve only marginal improvement. Remember, if the detail you're trying to put into the picture was not on the original image, even the best software can only recover (or simulate) some missing details at best.