October 2007
How they work
Aftermarket backup cameras have adopted various designs. A small video camera is sometimes built into a license-plate holder
or mounted in a trailer-hitch receiver or on a car's bumper.
Systems typically use a video screen built into a replacement rearview mirror, an accessory add-on monitor for the existing mirror, or a flat screen that mounts to the inside of the sun visor. Some systems are wireless, but most require wiring that snakes through the vehicle from the camera to the system's video display and on to the car's electric power system. Complicated, hard-wired systems are best installed by a professional.
Besides scouting for children, a camera mounted near, or in, the rear bumper can come in handy if you're trying to mate up your vehicle with a trailer. With a camera showing you where the hitch actually is, there's less need for a helper to call out directions to you.
None of the systems we've tested is ideal. The parking-sensor systems aren't discriminating enough to act as a truly useful safety device. Those that use a display built into an inside mirror seem promising, because the mirror is a natural place to look when you're backing up. But their display is often small, or indistinct, and the add-on mirror assemblies can be quite bulky. The viewing area from some cameras is quite narrow, and some cameras are prone to fogging up too easily.
Still, any camera system is more informative than a mere proximity sensor.
Systems typically use a video screen built into a replacement rearview mirror, an accessory add-on monitor for the existing mirror, or a flat screen that mounts to the inside of the sun visor. Some systems are wireless, but most require wiring that snakes through the vehicle from the camera to the system's video display and on to the car's electric power system. Complicated, hard-wired systems are best installed by a professional.
Besides scouting for children, a camera mounted near, or in, the rear bumper can come in handy if you're trying to mate up your vehicle with a trailer. With a camera showing you where the hitch actually is, there's less need for a helper to call out directions to you.
None of the systems we've tested is ideal. The parking-sensor systems aren't discriminating enough to act as a truly useful safety device. Those that use a display built into an inside mirror seem promising, because the mirror is a natural place to look when you're backing up. But their display is often small, or indistinct, and the add-on mirror assemblies can be quite bulky. The viewing area from some cameras is quite narrow, and some cameras are prone to fogging up too easily.
Still, any camera system is more informative than a mere proximity sensor.
