Light and its counterpart, shadow, are essential elements in black-and-white photography. In fact, the proper presentation of these characteristics can mean the difference between a striking monochromatic photograph and a boring one. For example, imagine a grizzled old man sitting on a park bench in full, noonday sun. His features would be washed out by the bright sunlight, making the image unpleasantly bright. Now imagine the same man sitting on a park bench, the side of his face warmed by the late afternoon sun. The shadows highlight each whisker and wrinkle, creating an image that is interesting for both its detail and contrast. Because these qualities are so important, it's essential that you know how to use light properly in your photographs.
As the example above suggests, not all light is created equal. Avoid shooting black-and-white photographs when the sun is high in the sky; this harsh lighting condition can obscure detail and make the images look washed out. Early morning and late afternoon, as well as overcast days, are the best times to photograph. If you're taking pictures in low light, bounce the flash off a ceiling or wall, or try to lessen the intensity of the flash. The effects of a direct flash are similar to those of bright sunlight.