Thursday, June 13, 2013

Geek Tip: Seeing Infrared

Infrared light is called "infrared" because it is invisible to the human eye. For this reason, TV remotes use infrared light to send signals to the television without bothering the humans in the room. Every such device has an infrared eye that should be kept clean to it'll work optimally.

There are some times when you want to see whether the TV remote is actually working or not. Sometimes the batteries are weak or dead and the remote doesn't have the power to send those invisible signals.

If you're a geek, you probably know that your smartphone camera has a sensor that is sensitive to infrared light. This means your camera can see what you cannot.

To see what I mean, have a friend aim the remote at you and push the power button and hold it down. If you've got a remote like I'm talking about (Some remotes use radio, those don't count.) there's a little LED light that to the naked eye doesn't look like it's doing anything.

Now, grab a smart phone or any digital camera, turn it on, and look at the remote through its display. If your remote is working properly, you'll see the LED light is flickering superfast.

Though the human retina is not sensitive to IR light, the camera's imaging sensor is sensitive to it. You can use this Geek Tip to see whether your remote's batteries are dead or not. Or just to entertain yourself if you're a Geek.

1 comment:

  1. I used this technique in a short film I produced years ago. The camera picked it up at 30p making it the only light in the darkness as the channel changed on the tv. Loved how it turned out.


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