Subscriber Discussion

Why Does The IR LED Have A Red Glow?

UE
Undisclosed End User #1
Jan 20, 2018

I have a couple cameras, one is a HIK with the EXIR LED (square one). On both cameras when the IR LED is on (like at night) the IR LEDs have a red glow to them that I can see. My photo camera sees it also.

Someone approaching can clearly see there's a camera mounted there because of this red light. I don't want this red sign on my camera telling people "hello there, I'm a surveillance camera and I can see you in the dark". I find the red light kind of annoying.

Does this happen with all IR LEDs?  I don't have enough cameras to know, but I would think not, otherwise people would be seeing the red lights all over the place.

Why is this happening? Is it the wavelength? I see some LEDs are 850Nm, some are 940Nm.

Is it the power of the LEDs? Is it the stronger farther reaching LEDs that do this?

(1)
JH
John Honovich
Jan 20, 2018
IPVM

#1, good question. the red glow is fairly commonplace. Wavelength is the main factor, 850nm is mostly used and it is not covert.

Our IR Video Surveillance Tutorial covers this, e.g., this image (from a PTZ with larger/ more IR LEDs):

940nm IR LEDs is growing somewhat with the benefit of being 'invisible' / no visible glow but with the downside of roughly half the distance covered for a given power output. An example of this is demonstrated in our Invisible IR Camera Tested (Vivotek) with the following relevant image:

Does that help? Let us know if we can answer further questions or expand on this.

(3)
UE
Undisclosed End User #1
Jan 20, 2018

This helps a lot ! Thanks.

Avatar
Scott Bradford
Jan 22, 2018
IPVMU Certified

Also cameras with 940nm IRs built in are pretty rare.  You are more likely to use a stand alone camera and stand alone 940nm IR illuminator. (which are slightly less rare than cameras with 940nm built in). 

 

 

It's big in hunting/trail/deer cameras, advertised as 'invisible IR'  but for CCTV it's hard to find    (former product manager for LE equipment)

 

(2)
(2)
Avatar
Christopher Moore
Jan 24, 2018
IPVMU Certified

To me the visibility is not a big deal because most video systems designed for our purposes are overt and can easily be seen during the day.  This (while there is no scientific proof that I know of) serves as a deterrent during the day while the IR can serve as a deterrent at night. 

(4)
CK
Carl Kristoffersen
Jul 19, 2018

But there are times where it's best that the camera not be so visible, especially at night and typically in residential applications.  Cameras can tend to blend in, but those red dots at night are quite prominent with no other lights on.  I had a customer with cameras on trees that could be seen from his house and in my case, I have a couple cameras close to the road that I would prefer not to be seen by others.  I also had a customer request an invisible IR for a camera on his gate.

New discussion

Ask questions and get answers to your physical security questions from IPVM team members and fellow subscribers.

Newest discussions