Although the majority of images are processed correctly, which means you'll get the type of prints you want, there are times when processing can go horribly wrong, particularly with film.

If your negatives are spotted, stained, scratched, or discolored in some way, there's a good chance they haven't been handled correctly during processing. They could also have been processed using chemicals that were old, incorrectly mixed, or kept at the wrong temperature. Scratches can also be caused by dust or dirt inside the camera. There's really not anything you can do to save negatives with these problems.

If your color negatives turn out under- or overexposed and you believe you exposed them correctly when you shot them, they may have been overor underdeveloped in the lab. These problems can be corrected to a certain extent during the printing process, but the prints won't be as good as those made with correctly exposed negatives.

Commercial, noncustom black-and-white labs are likely to overdevelop black-and-white film, which increases the contrast and makes light flesh tones pasty. This problem can be corrected during printing by changing paper grades, which will alter the contrast of the image, or by using a variable contrast filter with variable contrast paper. If your images were taken on an overcast day, increasing the contrast will make the blacks blacker and the whites whiter. However, this can distort other shades of gray, such as flesh tones.

File compression issues, such as files saved at too low a resolution, bad cropping issues, and images rejected because they look so good the lab suspects copyright infringement are the most common problems faced by digital photographers at commercial labs.

FIGURE 19-1 An online photosite that maintains your albums is a very good option for digital shooters. You can view and print from these uploaded files.

Before uploading a file or sending a CD to a commercial lab, carefully read the technical requirements on the website or at the lab. The technical data for sites may vary slightly, but the science behind the technology pretty much dictates that such things as minimum resolution and sizes are universal. Do read the help section to make sure you fully understand what you need to do.