I've been running some experiments with the cam before installing it. For that it was left staring at the garden through a window. I had the IR lights turned off.
To my surprise, when reviewing a night recording, I saw the four distinct glares from the IR light. My first thought was that the cam did not respect the off-mode and still synced with the IR-Cut filter.
But it turns out that it always bleeds some power to the IR lights when they are supposed to be off.
To test this, I set up the cam in front of a mirror in a dark room.
The first experiment was to set the shutter speed to 1/2000 with 6dB gain and cycle through all the IR settings:
https://imgur.com/pl8ffsTThe settings were: off, lowest, low, medium, high, highest.
As you can see, there is some light coming from the IR light in off-mode. Also, there is almost no difference between the high and highest modes.
The second experiment looked at how the off-light would affect the camera with the typical night mode settings:
The four images are:
1/6, 6dB gain
1/12, 6dB gain
1/25, 6dB gain
1/25, 24dB gain
https://imgur.com/zGXOMBCAs one can see, the light coming from the IR leds when they are supposed to be off is enough to blind the camera when it is in the typical night vision high sensitivity mode.
This is not a problem for me - I am going to mount it outside. But those planning on a through-the-window use will need to resort to the good and tested black electric tape.
Author
Topic: IR lights are never truly off (Read 8500 times)