Whether you're an amateur, intermediate, or pro photographer, there are a few common problems that can make otherwise good pictures candidates for the Recycle Bin. Some problems are fixable on the computer, others are not. Here is a short rundown of some of the most common problems and suggestions for fixing them, and, in worst-case scenarios, ideas for alternative techniques that may salvage the images.

1. Tilted horizon In a picture with a tilted horizon, the horizon line is not horizontal. You know the type—these are the pictures that make people tilt their heads when they look at them so they can get the right slant on the picture.

In-camera solutions Some of the newer cameras, both point-and-shoot and pro SLR models, help you get the horizon straight by providing viewfinder grid lines that you can use as you compose the image. Although I have a good sense of what's straight and what's not, I am off just enough and just often enough that I keep grid lines turned on as insurance against tilted horizons. And, if your camera offers an option for viewfinder gridlines, I recommend that you do the same.

In this image the horizon is tilted slightly. The tilt can be easily corrected in most image-editing programs.

If your camera doesn't offer gridlines, use the edges of the viewfinder to visually gauge whether the image is straight. Establish a visual measuring system for yourself, and then let your eye run from left to right across the bottom of the viewfinder to make sure horizontal lines are square, and then along a side of the viewfinder to check the alignment of vertical lines. If you're handholding the camera and the horizon isn't exactly at the bottom of the frame, it's difficult to line up the horizon and then shift the camera to recompose the shot while keeping lines straight. The best way I've found to ensure absolutely level lines in an image is to use a tripod.

Image-editing solutions Many image-editing programs offer ways to straighten tilted horizons. In most programs, you draw a line on the screen, and the software automatically aligns the image to the line you drew.

The result, of course, is that the image must be cropped side-to-side and top-to-bottom due to the shift. On some images, an alternative to cropping is to carefully clone image detail back into the areas that are cut off due to the shift. When I clone image area back into the picture, I always enlarge the image to at least 200 percent magnification to ensure that the clone results look natural and seamless.

This image shows the effects of wide-angle lens distortion known as 'keystoning' where the buildings appear to lean backward and lines converge, in this case, to the left.

2. Wide-angle distortion or 'keystoning' Keystoning is the distortion of converging parallel lines often seen in wide-angle shots. For example, in a picture of skyscrapers, the tops of the buildings converge to a point in the center of the image and appear to be leaning backward.

In-camera solutions Some amount of keystoning is often acceptable, and occasionally done intentionally for creative effect. However, to create a realistic depiction of the scene, you can minimize the distortion by:

Image-editing solutions Correcting wide-angle distortion on the computer can be trickier than straightening a horizon due to the amount of adjustment that may be required. Options for correcting distortion vary by image-editing program. In some programs, such as Digital Image Pro, you can use Distortion options, such as Vertical Perspective and Horizontal Perspective, to help correct the image, and then crop the image as a final step.

If your image-editing program offers a free transform option, you can use it to correct wide-angle distortion. The basic process is to enlarge the canvas first, select the entire image, choose the Transform command, and then drag the top image handles outward to 'widen' the tops of the buildings. Then you can use a distortion filter such as a 'Pinch' filter to reduce the rounded look of the image.

I say this is tricky because you may find that correcting the top of the image necessitates correcting the bottom of the image as well. The more corrections you make, the harder it can be to determine if the image is aligned fully. Be sure to use onscreen ruler guides, if your image-editing program offers them, as you make corrections.

3. Flawed image rescue And then there are those pictures that, regardless of in-camera skill or computer wizardry, are just plain technically flawed, but they have redeeming value —in other words, you don't want to pitch them, but you can't fix them either. Pictures in this category range from overexposed to underexposed, from soft focus to just plain blurry, from too saturated to totally washed out, and the classic mixed lighting image that doesn't look good regardless of how you adjust the colour.

These pictures may be unfixable in a traditional sense, but may be salvageable with alternative computer processing techniques. Certainly these techniques are worth trying before you press the DELETE key.

Image problem: Images with hue shifts and other difficult-to-correct colour problems may take more time to correct than you care to spend. This picture was taken in mixed lighting, which accounts for the difference in colours. Using the computer to color-balance for the primary light source did not produce acceptable results.
Try this: Convert to black and white. This option works especially well for images with good contrast, or images in which you can bump up the saturation without causing an unnatural or unattractive result. Depending on the level of control your image-editing program offers as you convert the image, you may need to increase both the brightness and contrast after the conversion. If you're using programs with channel-level control, try the channel mixing option so that you can control the tonal separation in the conversion. Retaining detail in the shadow areas will likely require experimentation.
Image problem: Focus is not tack sharp, colours are washed out, or images are overexposed or underexposed. Bumping up or reducing contrast and adjusting levels or curves doesn't improve the image enough to qualify it as a keeper.
Try this: Convert to sepia, duotone, tritone, or quadtone, or create a lightly tinted photo. Sepia toning is an inherently low-contrast technique that imparts a soft, antiquated quality reminiscent of the original nineteenth-century technique. Most programs offer a sepia tone or Antique option that you can use. If you choose the sepia tones yourself, stick with reds and yellows to produce a suitable brown. Though it's difficult to see at this image size, the duotone conversion improved the appearance of sharpness in this image. To lightly tint a photo, use the hue and saturation controls to shift the hue and reduce the saturation. For toned images, such as duotones, select the colour intensities that provide the contrast and mood you want for the image.
Image problem: Image has lack-luster colour, overly contrasty colour, or it was taken in overcast or otherwise lackluster light.
Try this: If the image tones are distinct, try converting the image to grayscale first, and then converting back to RGB. Then you can apply a new monotone colour. This technique can be a variation of the duotone process, or it can be applied using your image-editing program's colour balance feature.

These are a few of the problems you can encounter in day-to-day photography. Upcoming MSN Photos articles will detail other common problems with suggestions for fixes or alternative techniques. Be sure to visit MSN Photos often to check out the newest articles.

Charlotte K. Lowrie is managing editor of editorial content for MSN Photos. Her writing and photography have been published in magazines, including Quill (Society of Professional Journalists), Walking, and Texas Highways, and newspapers, including the Dallas Morning News.