Picture of an Infrared Reflection in a Window

Infrared Behind Glass

I don’t know too many people that love to get up in the attic or climb under the house to run cables. In fact, I would venture to say that I don’t know anyone that enjoys this project. However, it is a necessary part of installing a camera. In an attempt to avoid running cable or making permanent alterations to the home, I have been asked on many occasions, “Which camera would work best behind a window?” The fact is there is no good way to put a camera inside your home and point it outside. During daylight hours it is possible but still offers some challenges. After dark all that it is… well… out the window.

Have you ever tried to look out into the dark when the lights inside the house are on? Instead of seeing outside, you probably saw a reflection of yourself. In much the same way, your camera will see a reflection of itself.

Then, did you find yourself cupping your hands around your eyes and pressing them against the glass to eliminate the glare. You have just made an IR gasket, the same gasket in every IR camera. It’s there to keep the IR light produced by the camera from hitting the protective glass and reflecting back into the lens.

Picture of an Infrared Reflection in a Window

Infrared Reflection in a Window

Now think back to your last trip to the aquarium. Did you ever take a picture of any fish behind the glass walls of their tank? If so you know that you took a really nice picture of a fish and your flash. The light from an IR camera behaves the same way. Like the flash, the infrared light from an IR camera is an intense light that tends to reflect and glare on glass surface.

Unfortunately, as long as there is more light behind the camera than there is on the other side of the window, you have just created a mirror (See the picture for an example). The best solution in every case is getting a weatherproof camera and mounting it outside.

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10 Comments

  1. HELP/HELP PLEASE I need some info please. It’s on a infrared day/nite dome security camera (2) that I had installed this last week. The first nite I saw nothing but fog , not the images that I was suppose to see, but total fog out on both cameras.
    They are from SECO-LARM the ENFORCER (EV-122C-DVH3Q)
    CColor IR Day/Nite Weatherproof Vandal resistant Ball Mount cameras 24 leds 420 tv lines.
    I called the security systems business that installed them and told them of my FOG delima in the dark(nite-time). They told me that the cameras in order to work at night needed an alternate source of light. Told me to turn on my porchlight, yet I have a STREETLIGHT at the corner of my driveway which is maybe at the most 20 yards from the camera, maybe less.
    The reason that I got these was to see in the dark with the lights that I have surrounding me, I wouldnt NEED the cameras if I wanted to put up lights all around my house just to get the cameras to work at nite. MY QUESTION IS : IS IT TRUE THAT THESE CAMERAS NEED AN ALTERNATE SOURCE OF LIGHT, SUCH AS MY 100 WATT PORCH LIGHT TO MAKE IT WORK ? OR ARE THE CAMERAS DEFECTIVE AND NEED TO BE REPLACED.
    I SPENT OVER 1500.00 TO GET 2 CAMERAS INSTALLED AND I REALLY NEED TO KNOW.

    THANKYOU FOR YOUR ASSISTANCE AND HELP.

  2. Raedean,
    I am familiar with similar models of camera like the one you have. I can tell you that the infrared light that the camera supplies is in fact light that the camera can use to see in otherwise complete darkness. You do not need alternative light sources. It sounds to me like one of two things are happening. First and most likely, there is moisture in the camera causing a blooming effect when the infrared is on. You should be able to see that by looking into the lens for built up moisture. Second and much less likely, the possibility that the gasket between the infrared LED’s and the lens is allowing light through causing reflection. I hope this is helpful. If you have more details or more questions let me know.
    Chris

  3. hi chris, i just found your site by accident and HOPE you can answer my question…

    a few months ago an older guy moved in right accross from us, i could throw a stone at his house, it’s right accross the street.
    he put up some sort of beige window film in his 2 windows on the first floor – i also live ont he first floor. actually, his first floor is a little higher than ours, so from there he could look directly into our living room and my bedroom . . …

    he never EVER turns the light on in the first floor but does tilt the window daily for some time. i feel watched and i really wonder:
    could it be that he has a LED camera behind these beige window films, filming my daughter and me?????

    i feel so uncomfortable, we are even thinking about moving now. it is really weird!!!

    thanks so much for any answer you will find the time to give to us,
    kind regards,
    d and f

  4. First let me say that I hope nothing like this is actually happening. As far as whether or not it is happening, from the way you describe it, I would have to say it does not sound like it is.In fact, it sounds like just the opposite.
    I would say he is looking for more privacy. Putting a film up and keeping the lights of should make it more difficult for others to look in as opposed to easier for him to look out. If he actually does have a camera with LED’s behind the glass it would be difficult to get a clear picture in the dark. Putting a film on the window should make it more difficult.
    I hope you find this helpful. If you take a look at the article “Infrared Behind Glass” there is a picture of what I mean about the LED’s behind glass.

  5. Hi Chris,

    thank you so much for your answer!!!! It does make us feel a lot better!!!
    In the meantime, we constructed something like a fence out of fabric and wood poles and put it all the way around the balkony – just in case:-)))

    But I DO feel much better now, knowing that he can not really have a camera behind those taped windows!!

    Thanks you so much for your time ,

    kind regards,
    dagmar.-)

  6. I live in a condo corporation & they will not allow us to mount outside cameras. Police have told me I need camera evidence to catch the person robbing & destroying my property. Is there a reliable system for around $200 available in Canada (4 cameras) that I can use from my window. I am desperate. I am a prisoner in my own home!!!

  7. Karin. I’m going through a similiar issue with someone damaging my personal property. I’m going to look into getting a window security camera for my condo. I wa wondering did you have any luck finding anything.

  8. Why not just install a infared flood light or swap out your old bulbs for IF and mount the camera in a dark room/window?

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