Why Aren't White Leds In Cameras More Popular?

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Brian Rhodes
Dec 02, 2015
IPVMU Certified

For video cameras, why aren't white (visible) LEDs more common?

Most cameras that feature integrated LEDs use IR wavelengths, ie:

Uncommon examples of white LEDs in cameras can be found, typically in consumer grade models like this Axis cube:

However, adding light fixtures / using external white light illuminators is fairly commonplace.

Why isn't using integrated white LEDs more common? Should they be?

U
Undisclosed #1
Dec 02, 2015
IPVMU Certified

Because people don't like highly directional, low CRI, point light sources in occupied spaces?

The smaller and cheaper the emitter, the narrower the beam spread is likely to be. This is perceived as harsh.

Also, technically speaking there are no 'white LED's'. They achieve their whiteness by a combination of various wavelength LEDS and diffuser coatings.

Unlike integrated IR LEDs, which work fine being only one wavelength.

They may look white, but the hodgepodge spectrum filling, if not done well, will result in a poor color rendition. So you may not notice that your clothes don't actually match till you're outside.

(2)
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Brian Rhodes
Dec 02, 2015
IPVMU Certified

But using IR requires more componentry added to cameras, no?

Specifically IR cut filters. That Axis M10 is not a day/night camera, but the visible light LED illuminates an area such that a day-only imager can 'see'.

Also, the market for LED light bulbs has boomed, and a whole range of color temperatures are offered, so I'm guessing cameras could add diffusers or filters to blunt any harsh directionality.

U
Undisclosed #1
Dec 03, 2015
IPVMU Certified

But using IR requires more componentry added to cameras, no? Specifically IR cut filters.

Well, technically a visible light camera would require an IR cut filter more than an IR one, i.e. all the time, right? If you mean it wouldn't need the expensive (relatively) mechanism to switch it in and out of the focal plane, I'd agree, it wouldn't.

On the other hand mechanical IR cut filters are not present on a whole swath of lower end cameras which have IR. They just limp along with some lens coating which cuts out the longer wavelength IR, but leaves the rest as a compromise. (As you know that's why they can't really be focused that sharply.)

Again about the color temperatures being offered, these are combinations of LEDs and therefore not as cheap as a single diode, nor as efficient. Ditto the added cost in $ and lower efficiency for diffusers, as they absorb light to some degree.

And in any event it's just really hard to make a wide beam out of a directional point. And it's wasteful anyway to provide light outside of the FOV of the camera.

A couple of other observations:

Sensors are notoriously sensitive to IR. My guess is that in terms of apparent brightness, IR provides more illumination per watt. I'll look for some evidence to support this.

Finally, visible illumination is a visible give away to what a camera can likely see at night, where IR keeps you guessing, unless you have a cell phone.

Related: Does Your IR Illumination Advertise Your Blind Spots To Criminals?

(1)
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Brian Rhodes
Dec 02, 2015
IPVMU Certified
MA
Mohamed Ahmed
Dec 03, 2015

Sony has a camera and also new ameras coming from china lately come with both White LED and IR LEDs.

White LEDs are triggered for short distance motion detection thus giving a clear Color Picture and conventional IR (B/W) is used for overall night vision.

AT
Andrew Thomas
Dec 03, 2015

For interior lighting that will never catch on. Simply turn on the room lights. The move to GREEN buildings, and POE overhead lighting is going to rule the day in the coming years.

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Brian Rhodes
Dec 03, 2015
IPVMU Certified

I don't think lights on cameras will ever supercede an interior light fixture, and I am pretty intrigued by PoE lighting.

However, visible illumination on cameras is a separate Venn bubble; in almost every dummy camera and cheesy TV show, a CCTV camera has a blinking red light. In a dark corner, why not have a camera that emits light?

In alleys, dark parking garages, or lonely corners that might offer a net benefit for more than just video quality, right?

U
Undisclosed #1
Dec 03, 2015
IPVMU Certified

Ones that emit light on motion are definitely worth considering. I have two little cheap solar powered PIR lights next to two bullet cameras, so integrating that would be cool. But I still want the IR as well.

JH
John Honovich
Dec 03, 2015
IPVM

"Ones that emit light on motion are definitely worth considering"

And if the camera detects 'motion' 100 times a night? Seems like a nuisance problem waiting to drive people nearby mad.

U
Undisclosed #1
Dec 03, 2015
IPVMU Certified

It is a nuisance. My neighbor has a light that triggers on cars that go by as well as branches blowing in a storm. These cause motion alerts in my system, which if responded to in kind by me turning on my lights, a tragic case of sympathetic illumination could envelope the entire neighborhood in light in a matter of seconds. ;)

I don't know if his are tied to cameras, but you see these lights everywhere today, most often on the alley facing side of storefronts. Hopefully, if additionally tied to some rudimentary analytics they could be tuned more intelligently than they are today.

MI
Matt Ion
Dec 06, 2015

When it comes to outside "anti-prowler" coverage, I've always been partial to using a good day/night camera along with a motion-triggered white-light flood, with the thinking that if someone is creeping around at night and a bright light snaps on, the natural inclination is to look toward the light... and if the camera is right there beside it, that means looking right into the camera for a gorgeous, well-lit, full-color facial image.

U
Undisclosed #1
Dec 06, 2015
IPVMU Certified

How do you set the exposure to get a full color, well lit image the moment the bright flood comes on?

I would think it would have to be fixed because auto-exposure would not react quickly enough. But then the exposure might be set so low that you would get dark images at other times, e.g. dusk and dawn, no?

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Can Gürcan
Nov 05, 2020
CCTVDEPO

I believe it will change very soon. A strong light coming from the camera is simply "UGLY". As new low-light (starlight) cameras getting more popular, light requirement is getting dramatically low. Now a very low light (and yes soft light instead of white light) which can barely seen will be enough for the new gen cameras. I believe the future is low light cameras with low soft lights.

JH
John Honovich
Nov 05, 2020
IPVM

Note: this discussion is from 5 years ago. White LEDs have definitely become more popular in the last 2 years, led by Hikvision's smart marketing of them.

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