Night vision

  • 1 Replies
  • 2056 Views

0 Members and 1 Guest are viewing this topic.

*

paul.fr

  • Guest
Night vision
« on: 11/05/2007 02:24:18 »
I have night vision (not infra red) on my camera's, and have used night vision binoculars, but how do they work?

*

another_someone

  • Guest
Night vision
« Reply #1 on: 11/05/2007 04:14:06 »
Real nigh vision (the electronic ones) amplify the incoming light.

Not sure what they use these days - it could be just very sensitive CMOS light sensitive arrays - certainly that is all they could be using using for the camera.  On the other hand, the camera is easier because you are only looking to capture a still image, and if you need to take a 3 minute exposure for a single frame, that is no problem.  The binoculars are looking for a real time image, so you need to have the frame refresh about 60 times a second, so each image can only contain no more light than you were able to receive on the light sensitive detector within 1/60th of a second.

In the past, they tended to use a phosphor that emitted an electron upon receiving incoming light (like an old fashioned TV camera - opposite of the old CRT screens), but then either accelerated the electrons emitted from the surface with a high voltage, or passed them through thin tubes that would have that one electron knock more electrons off the side of the tube to create a cascade of electrons.