The sensors in digital cameras pick up more than just visible light. They pick up a lot of infrared too, that's light below red that we're not able to detect with our eyes.
This can make pictures look funny, so manufacturers add a filter to block the infrared and give you a more natural image. Actually the filters don't do a perfect job and if you fire a TV remote control at your camera phone you should see it light up on the screen.
All this means you can have a bit of fun with your old web cam. You can remove the infrared filter then add a visible light filter so your webcam only sees infrared!
I love Reddit but I don't get to visit every day and I worry about missing good stories. So I created this RSS feed of Reddit posts that score over 1000. Here's the feed link:
Ever since the invention of flat panel monitors and screens, it didn't matter what colour your pixels were, you'd still consume the same amount of power. That's because these screens have a big flat light at the back that's always on. If a pixel wants to show you white it lets all the light through. If it wants to show you black it blocks all the light. Either way, the light behind is still on and still consuming the same power.
