More recently, digital SLRs have added autofocusing while shooting video to their bag of tricks. Because video-mode auto-focus relies on a different technology than is used when you take still photos, it is actually a bit slower and less accurate, but a dramatic improvement over, well, no auto-focus at all.

Get published, get famous! Each week, we select our favorite reader-submitted photo based on creativity, originality, and technique.

Here's how to enter: Send us your photograph in JPEG format, at a resolution no higher than 640 by 480 pixels. Entries at higher resolutions will be immediately disqualified. If necessary, use an image editing program to reduce the file size of your image before e-mailing it to us. Include the title of your photo along with a short description and how you photographed it. Don't forget to send your name, e-mail address, and postal address. Before entering, please read the full description of the contest rules and regulations.

This week's Hot Pic: "Touchdown!," by Tim Marshall, Bayonne, New Jersey