Most face-detection implementations, whether done in hardware or software, look for two eyes, a nose and a mouth, though some companies now claim that their technology is able to detect faces in full or three-quarter profile. Once the software has identified a face, the software will highlight it in the viewfinder and track the face as it moves. Additionally, the software can adjust the image, focusing on the face, for example, and tracking while a person moves.

You may be thinking, what happens when there are non-human faces in a frame? From what we've seen of them, all of them are designed to pick up on human faces first and foremost; but of course, there are differences in all of the face detection algorithms currently available. Having said that, though, there are animal-specific face detection algorithms that are used in scientific contexts. These would only be truly useful if you're actually on a scientific mission, though. Unless you happen to make pet videos for a living… but that's your business.

So far, all of the camcorders we've seen that include face detection also let you turn the feature off. Why would you want to do that? An artsy shot with flowers in focus and the subject holding them in soft focus is a good example of when you might want to turn this feature off.

The only way to know if facial detection technology will help you in your production endeavors is to try it out. Never experiment on an important production - spend an afternoon in a test environment, similar to your "real" shooting, simulating your normal shooting conditions, and see if facial detection is helping your images and helping you do your job with less effort.

Contributing Editor Kyle Cassidy is a visual artist who writes extensively about technology.