When I bought a new house last summer, one of the first pieces of technology that I wanted installed was a video camera pointing at the front door. Not just any video camera, mind you: I wanted a genuine surveillance camera to record the comings and goings of both authorized and unauthorized visitors to my house.

Why? The desire stemmed partly, I suppose, from experiences at my previous residence, a second-and-third-floor walkup in West Cambridge, MA. When its front door rang, I was invariably in my office on the third floor. I went to the trouble of installing a buzzer on the front door, only to discover that it made me nervous to let people in without looking them in the face. So the buzzer went unused, and I invariably ended up descending two flights of stairs to see who was there.

My family's new house is a three-story single family in a quiet Boston suburb. There's really no crime problem here, but like many homeowners, I saw in my new home an opportunity to correct every problem with my old one. So when we had electrical work done, I asked my electrician to run a video cable from the porch to the basement and a companion cable from the basement to my bedroom on the third floor.

Installing an outdoor video camera poses a unique set of hurdles. The first is water. Although any video camera can be protected from rain in a watertight enclosure, you're better off buying a weatherproof camera and putting it under an awning. A second problem is illumination. Prolonged exposure to direct sunlight can damage cameras designed for indoor use. For night time use, meanwhile, you'll want a camera that's sensitive to low-light or infrared light. You'll also want an infrared illumination source.

Sound complicated? It's not. The camera that I installed is a $200 weatherproof unit I bought over the Web from SmartHome. The size of an Idaho potato, it's a color camera during the day, an infrared camera at night, and even sports a ring of infrared LEDs to illuminate the nighttime scene.
 
Although I could have installed a 2.4 gigahertz wireless camera that transmits to a computer or a television set, I opted for a video cable instead. Not only did I want to avoid interference with my wireless home network, I also didn't want other people in my neighborhood to be able to pick up my video stream. And since I was already running an electrical line to the camera, the second line wasn't much more work.