Originally Posted by SamuraiBigEd
There are some very efficient infra-red emitters out there, single chip units that can illuminate for night vision up to 100 yards away, you won't find these in backup cams (or security cams either) but their led cousins are getting pretty potent. I have seen back-up cams that can illuminate 20-30 feet behind the vehicle without any lighting from the vehicle.
It's been 5 years since I last looked at LED cameras. At least back then the near-IR (they glowed cherry red, not very stealthy) LEDs used in the cameras that I tried were ridiculously weak compared to those used in other applications. (And a good LED IR panel cost $750US.) The 120 LED camera that I had claimed to reach 120 feet, but in real-life the camera, which produced a beautiful and sharp picture in daytime, couldn't see anything beyond the 20-30 feet away where my cars were, even with the overhead sodium vapor parking lot lights helping. And that night image was not nearly as clear as the daytime image.
It's reasonable to believe that things have improved since then; I hope so! When I made my first post I had forgotten how long it had been. I suppose it also matters what level of image quality you find acceptable. I needed to be able to read the license plates of the cars that were hitting mine. I don't know what kind of detail you'd need for a backup camera.