What is Lux: Shedding Some Light on Low Light Cameras (page 2)
Electronic Enhancement
Single-chip cameras do have the ability to make do with very little light. When there isn't enough light, the camera takes what light it does have and amplifies it electronically. This is a reasonable strategy, but the resulting picture is less than perfect. Amplification of a low-light signal inevitably results in graininess and video noise. The situation is like audio tapes that were recorded at too low a level. When played back on your stereo, you can hear the music, but just barely. When you turn the volume up or amplify the signal, you hear the music better, but you also hear a lot of hiss as well.
The same thing happens with amplified video signals. The camera will amplify what little light it does receive but along with it, you will receive plenty of video noise. The resulting picture will have a grainy, colorless look. Sure, you can see your subject, but it is far from the quality you are after.
Keep these factors in mind when looking at lux ratings. Is a camera rated at 1 lux because of its superior optics or because of electronic circuitry? In the end, a side-by-side comparison is the only true test. In doing so you'll find that optics will win out over electronics when it comes to low-light shooting. Of course, for professional-looking video, it's best to forget low lux ratings and invest in a light kit.
[Sidebar: Pitch Black]
Recently, we've seen a lot of extremely low-light video on the news as videographers have been forced to shoot in no-light situations during the war in Iraq. While the quality of the video is low, it's better than no video at all. Here's how they do it:
