I recently got a Nintendo Wii console, which is super-duper amazing. I must admit I do get the reaction of "OMG you bought the only console with crap processing power, graphics and lack of HD output", but the main thing is it is what any games console should be: fun. (see comic at bottom of post)
I had some problems getting the position of the wiimote to be sensed correctly but I quickly realised that was due to the fault of background light. It seems that the sensor bar emits infrared light which the Wiimote picks up and "triangulates" to measure change in position, etc.
Anyway, if none of you believe me: here’s a picture of the Wii Sensor Bar with Infrared:
For those of you who aren’t trained in physics – light comes in electromagnetic waves. The visible light we see has a wavelength of between 400nm and 700nm. When the wavelength is longer than red (which has a wavelength of 700nm), it is infrared.
We can’t see infrared because it is beyond the spectrum our eyes can perceive, but we feel it as heat. TV remote controls use infrared.
Digital cameras have "Charged Couple Devices". These are designed to pick up light and to convert it into a series of 1s and 0s, so we can view them on a computer. The problem is that CCDs are generally made with a wavelength range of about 350nm to 1000nm so they will pick up infrared (heat), which can give strange photos as our eyes don’t percieve this part of the spectrum.
To get around this, camera manufacturers put filters to block out infrared light. Because mobile phone cameras tend to be of a poor quality and are very compact, they only have a thin film of filter, meaning it will pick up infrared. This is one of the reasons why photos taken on mobile phones are inferior to real digital cameras.
However, we can harness this problem with mobile phones and take images in infrared. If you put a phone cam in front of a TV remote control and press some buttons, you should see a succession of rapid flashing. The same happens with the Wii sensor bar allowing you to take an image of the infrared emitted from the bar.
Cyanide & Happiness @ Explosm.net