Subscriber Discussion

Using IR Camera Inside Elevator

UE
Undisclosed End User #1
May 28, 2015

are there known issues of using ir camera inside an elevator, like reflection of ir on the elevator wall?

(knowing that there is always an emergency light on every elevator, but in case there is none)

JH
John Honovich
May 28, 2015
IPVM

Good question.

I have not done IR inside an elevator. However, one fundamental concern / question I would have is whether the IR power would be too strong, since the IR illumination would be reflecting off walls no more than 10 feet away. By contrast, most IR is designed to be used over wider / more open areas.

Let's see who has experience with this.

MI
Matt Ion
May 28, 2015

Only ever done a few elevator camera, none with IR, but I agree with John, most IR would completely wash out anything in such a small space. Options might be a camera with some form of "smart IR" that can dial back the output, or if you're feeling adventurous, manually disabling some of the LEDs, either by covering them up, or by disconnecting them.

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Simon Barnes
May 28, 2015
Never done it but Matts advice to use something with smart IR would be my recommendation. Try one of the Hik 2 line domes they have that feature and are cheap enough to see if it would work. I have tried smart IR in a small place and it does work, one question does the lift have mirrors?
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RT
Remus Tomici
May 29, 2015

The biggest concern in using an IR elevator camera is interference of the camera IR light with the elevator door sensors. I would never recommend using IR lights inside an elevator cab. Elevator cabs have constant lighting for most of the time and enough lighting to accomodate even the worst of cameras.

Not sure the liability added by use of an IR camera outweighs the lack of video while a cab is shut off or the elevator light bulb goes out.

MI
Matt Ion
May 29, 2015

This is a very good point, if the elevator uses optical sensors for door obstructions. If it has a mechanical trigger, you're good to go, but depending on how reflective the inside of the elevator is, the IR could cause issues with the door closing properly.

U
Undisclosed #2
May 29, 2015
IPVMU Certified

The biggest concern in using an IR elevator camera is interference of the camera IR light with the elevator door sensors.

Remus, that sounds quite plausible, since elevator doors DO commonly use IR beams and sensors for obstruction detection. But I'm not convinced that a ceiling or corner mounted IR camera would actually create such a hazard, even in a Vegas-style, mirrored, wainscot-less cab.

Because a single, everyday incandescent 100W light bulb generates more IR radiation than a typical, low-power/short-range IR LED ring, by a good margin. Not to mention Sunshine.

So considering that many elevators sensors apparently are not affected by the presence of multiple high-wattage, black-body luminaires, as well as the continual bombardment of infrared rich daylight, striking the doors at all angles, I'm wondering how the 2 Watt LED ring could even make a difference.

Besides when would the camera ever even switch to IR to begin with? Since normally an elevator cab is lit, and in the case of a power failure, one would expect that a cab light would be fed by emergency power before a camera would be.

Even in the pathological case of a cab with a single light bulb that burns out during travel, the doors would be closed and the sensors would be blocked until reaching the destination floor, when the doors would open to the presumably lit vestibule and thereby cease IR emittance.

Maybe I'm wrong, though. What do you think?

(1)
MI
Matt Ion
May 29, 2015

Because a single, everyday incandescent 100W light bulb generates more IR radiation than a typical, low-power/short-range IR LED ring, by a good margin.

I can't even think of a time I've been in an elevator that used incandecent bulbs. For decades, most have used fluorescent, and now they're moving to LED.

For that matter, it's highly unlikely to find a commercial or multi-residential building (where you're going to find most elevators) that uses incandescent in their public areas (where you're going to find most elevators).

Not saying you don't have a point about light bulbs and IR... just saying it's extremely rare to find incandescent and elevators together in the first place, for completely different reasons.

U
Undisclosed #2
May 29, 2015
IPVMU Certified

I can't even think of a time I've been in an elevator that used incandecent bulbs. For decades, most have used fluorescent, and now they're moving to LED.

I'm impressed with how luminaire-aware you are!

And although I don't know exactly what elevators you have been on, I would challenge you to look up next time you are on a elevator in a upscale hotel or other semi-posh setting, if you don't see a diffuser, but instead see circular point sources they are most likely halogen/incandescent fixtures. Personally, I can't remember such things, but my wife who runs a small LED retrofitting company insists. :)

RT
Remus Tomici
May 31, 2015

In our case, the IR camera was installed in the far corner of the cab, hitting the door sensors at 45 deg angle. The door was held open and the built in safety mechanism of the elevator prevented the car from moving. The elevator mechanics were the ones involved in the troubleshooting and they reported the issue.

U
Undisclosed #2
May 31, 2015
IPVMU Certified

The door was held open...

Normally doors are held open only when IR is BLOCKED.  

Is there any theory on how the additional IR of the camera would cause the IR from the transmitter to be blocked?  Oversaturation shutoff?

Also, were the lights off in the cab, else why would the IR even come on? Lights out testing?

BTW, If this is a case of a camera's integrated IR interfering with the IR receiver and preventing the door from closing, then it could have general applicability to a very common situation: 

Namely, IR cameras in garages with automatic infrared garage door sensors.  

If the auto-incadscent light bulb of the door opener is burned out (mine is), someone exiting the garage thru the side door at night would naturally hit the close door button, turn off the overhead light, and shut the door.  At this point the IR would begin to come on, and could cause the door to not close or reverse.  But I don't think it would stop closing.

MI
Matt Ion
Jun 01, 2015

If the auto-incadscent light bulb of the door opener is burned out (mine is), someone exiting the garage thru the side door at night would naturally hit the close door button, turn off the overhead light, and shut the door. At this point the IR would begin to come on, and could cause the door to not close or reverse. But I don't think it would stop closing.

A key difference here, though, is that garage door sensors use a single, very tight beam, and the receiver is generally protected from outside light interference, either by being placed at the end of a tube, or with a lens, or both. They typically won't detect any IR source that's not shot directly into them, and the receiver and emitter have to be lined up quite carefully to function.

U
Undisclosed #2
Jun 01, 2015
IPVMU Certified

Matt, likewise elevators sensors are typically recessed in to the door to restrict the light entering to a given plane, thereby limiting interference from off axis angles, same idea in 2d instead of 1d.

MI
Matt Ion
May 30, 2015

I'm impressed with how luminaire-aware you are!

Thanks... I think? Luminaire awareness comes in handy for baiting the anti-CFL crowd... ;)

And although I don't know exactly what elevators you have been on, I would challenge you to look up next time you are on a elevator in a upscale hotel or other semi-posh setting, if you don't see a diffuser, but instead see circular point sources they are most likely halogen/incandescent fixtures.

Actually, now that I think about it, I can think of one elevator that has four small halogen floods (the mini-PAR types) and brushed stainless walls. I remember what a pain those fixtures where when I had to take one of the ceiling tiles out to install the camera...

Other than that though... the vast majority of commericial fixtures still tend to be fluorescent.

U
Undisclosed #2
May 30, 2015
IPVMU Certified

Probably enough exist though that we would know if they were causing doors to erroneously close, right? ;)

One question though for the OP, are you stuck with IR cameras and just making sure they are OK to use?

Or are you trying to actively use the IR for some scenario?

MI
Matt Ion
May 30, 2015

Probably enough exist though that we would know if they were causing doors to erroneously close, right? ;)

Not really... if it did cause an issue, one would hope either the door on that specific elevator was designed to accommodate it, or the installer would have dealt with it right off the top. And remember that not all elevators use IR/beam sensors - some still use a mechanical bar (obviously these would not be affected by camera IR).

UE
Undisclosed End User #1
May 30, 2015

Im just making sure if it OK to use. An integrator mentioned this to me based on their experience and I have no idea if this is true .

U
Undisclosed #2
May 30, 2015
IPVMU Certified

Well, in that case the thing to do would be to contact the elevator manufacturer. Do you have a manufacturer/model in mind?

Also, curious what circumstances did this occur under? Power outage where the camera still had Power? And one would think it would make the door accidentally close, right? That's far harder than making it open accidentally because it requires the whole length of IR receptors be triggered.

UE
Undisclosed End User #1
May 30, 2015

Im just curious if it is true that reflection of ir can make the camera "blind" or make unusuable image in a stainless steel elevator.

U
Undisclosed #2
May 30, 2015
IPVMU Certified

As was stated earlier, it's likely that if the elevator was dark, and the IR was triggered, that the size of the cab and the amount of reflection would cause some parts of the image to be over exposed.

But again, when would the cab be dark and the camera be working?

UE
Undisclosed End User #1
May 30, 2015

I hope ipvm can make an experiment on this.

JH
John Honovich
May 31, 2015
IPVM

This is such a rare case and it is not even clear the value of putting IR inside an elevator that this is not likely something we would test.

If you do choose to use IR in an elevator, please ensure that the camera allows lowering the IR power because even cheap IR cameras are designed to be far more powerful than what is needed inside an elevator.

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