Disabling automatic gain control on consumer cameras

Lower cost consumer level cameras do not provide a switch to turn off automatic video gain. When the scene gets dark, the automatic exposure opens up the aperture as much as it can – and if that does not let in sufficient light, then the camera starts amplifying the heck out of the video signal as the automatic exposure tries to make everything look like daylight.

The result is that interior scenes and anything shot at night end up looking horribly grainy due to the video amplification.

There are a number of tricks in use to over ride the video gain.

  1. The slightly hard one, in practice, is to point the camera at something bright enough, and then select the exposure lock feature, if the camera has that capability. Then point the camera back at whatever it is you want to look dark without tons of amplification noise. This is impractical for most “live” recording but works well for static subjects and short scenes.
  2. Another is to try one of the camera’s automatic settings – such as “fireworks” or “spotlight”. I’ve had excellent results using the fireworks setting for outdoor night time scenes that did not involve fireworks. The spotlight mode is for such things as stage lighting – where the subject is brightly lit but the background is typically dark. Most cameras mess up the exposure turn the subject into a bright white smudge in order to expose the background. Where I can, I usually set exposure manually, but you might also try the spotlight automatic setting if your camera as that ability.

I attended the 2010 Consumer Electronics Show in Las Vegas in January.  The only camera I took along was an older Canon HG10. I set the camera to record in its 24p mode and selected, usually, the fireworks setting, to get some excellent results with outdoor night time shots using what ever lighting was there.

Example – you can watch this in full screen mode to see how clean the video looks – and yeah, this is an inexpensive consumer grade camcorder, the Canon HG10.

You’ll get much higher quality on the video if you go directly to the Vimeo page itself rather than using the embedded player. Go to:

Canon HG10 night time video shot sample from coldstreams on Vimeo.

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