LED Lighting & CCTV

Our clients are concerned that converting to LED light fixtures will adversly affect the performance of their CCTV system. Their concern is LED light fixtures do NOT contain any IR energy in their light spectrum and this will impact the quality of CCTV picture on the exterior of the building.

In my opinion, although the LED's fixtures do not provide an IR signature, IR can be detected from the surrounding area. The cameras are more interested in the amount of white light being broadcasted. The 1 - 3 MP cameras are so sensitive in a low light environment that the built in IR cut filter can provide adequate color images. The key is to specify day/night cameras and within the parameters of the lighting levels


How do the LED light fixtures light output compare to the existing light fixtures? Weaker? Stronger? That's probably a bigger factor than IR light available.

The lighting levels will be increased to comply with the IESNA security lighting standards.

Is a test possible? Convert one fixture to LED to see how it impacts night images? LED lamps are quite complex, and the degree they bleed into the IR wavelength depends on the bulb.

I'd agree with John. If the lighting levels are actually going to be increased, whether you're in color or monochrome, the visible light is making more of a difference than IR. In all the tests I've done, the gains with the IR cut filter off compared to on under the same light are typically slight.

If you take a look at this recent image from the Panasonic 4K/12MP test, there's not a significant difference between color and monochrome here.

But was the light source incandescent?

No, LED.

Since lighting LED's have very little IR in them, the IR Cut filter shouldn't make much of a difference. And it didn't.

IMHO, you would have to test with tungsten, halogen or natural sunlight. All of these have a significant amount, (>40%), of IR, that would be reduced by the filter.

I did a simple indirect light (~1 lux) test between a halogen and led with a SNB-5004 set to AGC off and shutter of 1/4.

IMHO,

  1. the Halogen Mono image is clearly brighter than the LED Mono pic.
  2. the Halogen Color image is slightly brighter than the LED Color pic.

The first statement, taken without any IR filter, is easily explained since camera sensors are typically sensitive to IR and the infrared component of a halogen lamp has a significant IR component to it, as shown here:

In the second case, though one might argue that the IR filter should eliminate the IR reaching the sensor, so they should be the same. IMHO, optical sensors are not hard-pass filters, they taper and so rather than reduce any visible light, they err on the side of letting a little of the shorter-wave IR thru. Not much, but detectable in the case of halogens.

A unscientific but convincing way of demonstrating the sensitivity to IR even with the cut-on is is to take a remote control and fire it at a security camera in color mode. I did:

In the OP's case though, since he intends to use low-light cameras in color mode, the extra IR illumination lost would be minimal, and most likely made up by even a small increase from the new lights.

On the other hand, when replacing incadescent or halogen with LED's, and in cases where one is switching to Night mode without any additional IR, the difference could be significant.

In either case the one thing to keep in mind is beam spread and CRI (color index) of the new fixtures vs. the old. LED's can be extremely directional, they have a "FOV" just like cameras but in reverse.

So even if brighter overall, you will likely find after the conversion spots that are better illuminated than before and vice versa.

Full disclosure:

My wife runs a small LED retrofitting company which I interfere with in my spare time. :)