The fill light is about two stops dimmer than the key - you can soften it by backing it up, changing the power setting (if your lights have variable power) or using a diffuser to cut back the amount of light. You place it on the opposite side from the key light, at about the height of the camera. There may be a temptation to put it at the same angle as the key - after all, we like symmetry - but don't do that. One thing we're trying to do here is use shadowing to make the two sides of the face look different, so try your fill light at an angle of 15 or 25 degrees, and adjust it to suit your aesthetic.

The back light illuminates lights the space above and slightly behind the model. Photographers sometimes call this a rim light or hair light. Its purpose is to give some sense of separation between the model and the background. Using it in a dual purpose, the backlight can also become the background light, rimming the back of the subject while spilling across a background, especially one with some texture, such as fabric. This background light can be snooted or gobo'ed, illuminating some small part of the area behind the subject.

The minimum number of lights that you need to do three-point lighting is ... one. You can actually do three-point lighting with a single light, by using the sun and a reflector as your key and fill. But for all practical purposes, a three-point lighting kit should have at least two lights and a reflector. Use key and back lights with a reflector for the fill. Reflectors can range from a $300 Photoflex kit with gold and silver collapsible fabric disk reflectors, a diffuser, and an adjustable stand to hold it properly, or it can be your cousin Leon, holding a copy of Led Zeppelin IV wrapped in tin foil or a folded bit of foamcore with coffee stains on it. If you really want to look super cool, you can buy one with a Videomaker logo from the magazine's website (it'll look great with your Videomaker hat).

The advantages of using only two lights are obvious: there's less to carry, you have less chance of blowing the power and the reflectors are already diffused, which means you don't need an extra umbrella or softbox. Nowadays, most three-point lighting uses diffused light. In the past, it included harsh lights, which accentuated shine on people's faces and cast sharp, unflattering shadows. A three-light kit can go from $150 up to several thousand dollars. Some come with hard-shell traveling cases, diffusers, softboxes, etc., and others are much more basic. It's probably best to start simple and work with it until you know how much you're liable to use it.

Why do we always talk about three-point lighting? What's so great about it? Well, the truth is, it's not so great, and it's not the best or most creative lighting setup for any given situation. But the reason that you need to know it is that it's a starting point, and it's almost always good enough. Imagine you're a photojournalist, sent on assignment to videotape an interview with a famous scientist. You show up in her lab only to discover she has 20 just minutes before she needs to be on a plane to Florida to tag sand fleas. What do you do? Three-point lighting. Because you've practiced, you know you can set it up in your sleep. On assignments where you have more time, you can experiment to find the best, most creative lighting solution, using this as a start. It's an essential part of any videographer's visual vocabulary.

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