IR lighting too bright

[bigbadw]

I'm trying to find a way to illuminate an area at night, without being obnoxious or obvious. It looks like the standard nighttime IR lighting is very bright for the cameras. In reading there is something called "covert IR" that is in the 940-950nm infra red range.

I'm not finding the specs on the cameras that show what light range they support. Has anyone researched this area yet? Are the existing cameras able to use that IR range?

 

[bp2008]

The way I understand it, some camera sensors are sensitive to that longer wavelength IR, but not nearly as sensitive as they are to the 850 nm IR. It is something like 1/3rd the sensitivity I think. Though I have no facts to back this statement up. Unfortunately, I cannot say how sensitive our popular Hikvision and Dahua cameras are, as I don't have any 940/950nm illuminators.

You might try an infrared remote control (like for a TV) in front of your cameras at night to get some idea of their sensitivity. Most IR remotes use 940nm I believe, but you should be able to verify this by looking at the LED yourself -- if you see any red glow at all, it is probably a 850nm LED instead of a 940nm LED. Once you've found a remote control that you can't see light up at all, try it in front of the camera (in the dark), to see how sensitive it is.

 

[nayr]

you cant see the illuminated area with a naked eye; the camera will adjust to the brightness.. the more IR light, the more detail.

 

[bigbadw]

Thanks for the feedback, I will try a couple remote controls and see what they do.

The issue I'm having is the camera IR Leds being bright themselves. As you drive down the road, the camera stands out at night glowing red like an insane beacon saying "here I am".... So, a potential solution is to move into the Infra Red past human visible range. I see some 12 volt lights in the 940-950nm IR range and am trying to find an IP camera that is tuned to that range.

So far, what I am reading is; As IR becomes more covert it becomes more difficult for the camera to see and consequently distances are reduced. 940-950nm IR should only be used with highly sensitive cameras fitted with high performance lenses. Focussing is also more difficult at those wavelengths as lenses start to operate more inefficiently with 940-950nm.

This may be a highly specialized area and not that many people have investigated this yet.

 

[nayr]

this is how it is; the only cameras "tuned" for 940-950 are gimmicky cameras with poor performance.. they cost too much and perform too poorly, designed only to empty the pockets of people turned off by the red glow and dont know any better.

lighting in that range with normal cameras is very poor, your better off using traditional lighting and turning off IR if you dont want the camera glowing.

my recommendation is to live with it, you'll waste alot of money to get worse performance.. if covert operation is required your better off with no IR on a camera with extremely good low light capabilities and some standard visible security lighting to keep ambient lighting adequate... with enough visible lighting you might even retain color operation throughout the night which is a good thing.

 

[bigbadw]

Outstanding advice. Thanks nayr.

 

[paarlberg]

If you want covert, thermal cameras would work. But you will need deep pockets.

See if your camera has a smart IR option, my Hikvisions do and I think it will adjust to prevent being too bright, which would mean lower IR output.

 

[bp2008]

I think Smart IR just dims the IR when something gets washed out by it, and won't have the intended effect of making the IR impossible to see.

 

[paarlberg]

I agree, but it might reduce it some.