You probably want the brightest ones (usually measured in in mcd) you can get! Besides that, if you know anything about the camera you are using that would help a lot, for example which part of the spectrum in nanometers it is most sensitive to. Then you can match it to the spectrum emitted by the LEDs.

Another characteristic is the angle of the LED, in your case you probably want them to be pretty wide.

Some LEDs are low current or ultrabright, which mean they are better at making light from current. Ultrabrights, however use a ton of current at their brightest. This is usually only a concern if you are running from a battery or very weak power supply (or in something like a voltage controlled synthesizer when a sudden big current draw can have audible consequences!).

So once you understand the characteristics of the LEDs, you can choose the ones for your budget. You'll still have to do a lot of testing to get the right amount of light for the space and your camera. It's always of a question of whether you have more money than time, or time than money.

Somehow I seem to have neither these days, I wonder what I'm doing wrong! ;-)

Best, Derek

On 8/30/10 4:44 AM, ronni montoya wrote:

Hello everybody, i dont know if here is the correct place to ask, if anybody know another forum related to this , i will be very happy if somebody can show me:

Im making an interactive floor and i need to iluminate a space of 4 x 4 meters with ir light. I been seen there are some ir leds matrix on survillance stores but they are expensive to my budget, so i was thinking that i can build my own ir led matrix . I been seen there are tons of different types of ir leds with different characteristics.

Do anybody know which ir leds do i need for this?

which model, label or serial number?

Any idea would be appreaciated

thank you very much

Ronny

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