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IR lights reflecting off of windshield

  1. Apr 1, 2013 #1
    I am considering purchasing an in-car camera such as this:
    http://www.ebay.com/itm/Vehicle-Car...tal_Video_Recorders_Cards&hash=item4171ce36d5


    The device has six infrared lamps to illuminate at night. I am concerned that a good portion of the light of those lamps will be reflected off the windshield and back at the driver and passenger. In addition to showing the reflection in the video, might there be any health effects from having this excess IR light in the cabin at night? Might it cause eye damage (seems unlikely, as there is other IR around, but this is probably more intense). Might it cause the pupil to contract, thereby reducing night vision? Are there any other ill effects possible?

    Thanks.
     
  2. jcsd
  3. Apr 1, 2013 #2
    What do you want those lamps to do?
     
  4. Apr 1, 2013 #3
    it does not matter what I want them to do. What matters is that they may have unintended consequences of being lit. I was hoping that someone familiar with light, specifically the reflection of IR and human physiological responses to IR, would address the concerns mentioned.

    I might be able to disable the IR LEDs by crushing them with pliers, but before I consider that I would like to hear an informed opinion.

    Thanks.
     
  5. Apr 1, 2013 #4

    nsaspook

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    I have a similar cam in one of my cars (that monitors teen drivers). You can turn off the IR leds in the setup menu. They (IR leds) were useless to extend the units poor night-vision anyway as the IR brightness is very low.
     
  6. Apr 1, 2013 #5

    Drakkith

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    Staff: Mentor

    The LED's don't put out nearly enough energy to harm you and I don't believe your eye responds to IR light, so you shouldn't have to worry about losing your night vision.
     
  7. Apr 2, 2013 #6

    CWatters

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    Google found article here suggesting a safe limit is 100W per square meter..

    http://www.safetyequipment.org/userfiles/File/ProUp_Oct09.pdf [Broken]

    As I understand it the problem with IR is that it doesn't cause the pupil to react. That means more IR light reaches the back of the eye increasing the risk of damage. However I agree with others that the level produced by these LEDs is very unlikely to cause any problems.
     
    Last edited by a moderator: May 6, 2017
  8. Apr 2, 2013 #7

    AlephZero

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    If the lights are supposed to be illuminating the whole field of view of the camera, they shouldn't be producing focused beams. You are right that IR lasers are dangerous for the reasons quoted (and because that you can't see the beam at all) but these are LEDs, not lasers.
     
  9. Apr 2, 2013 #8
    Thank you. Turning the LEDs off is certainly preferable to popping them with a plier!
     
  10. Apr 2, 2013 #9

    Bobbywhy

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    Gold Member

    A small piece of duct tape will block all the radiation, if you just apply it over the emitting LEDs.
     
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