Now we're getting to the good part. Increasing contrast is one of the best ways to improve images, often dramatically. Images with good contrast can seem to "pop" off the page and appear to have more detail. If you are familiar with the previous Lightening and Darkening sections in this chapter, learning about increasing contrast should be relatively painless since it basically amounts to lightening the lights and darkening the darks.
There are a few things to beware of. The main thing is to be careful not to over-lighten or over-darken any area to the point that your image loses detail in areas that are important to you or that need to be preserved for reproduction on its destination device. For example, the lightest areas in images destined for print need to be a little darker than pure white and the darkest areas a little lighter than pure black to maintain print quality in a typical image.
This is because of the limitations of the output device, such as a printing press or printer. Limiting lights and darks is not as much of an issue when you are preparing images for Web, since monitors don't usually have as many tonal limitations as printing devices. However, displays can vary significantly in how they display images.
It pays to learn how to generally or specifically target certain parts of an image when you are doing the lightening and darkening for those times when a more global adjustment doesn't do a good job. The Lightening and Darkening ...