Ultra "Bright" IR LEDs source?

"Mark" schreef in bericht news:A+ snipped-for-privacy@mxnet.demon.co.uk...

What camera are you using? Not all cameras are equally sensitive to infrared.

Make sure your camera has no IR filter. Usually a little surgery will allow you to remove the IR filter if there is one. It's usually just a thin film you can simply remove.

--TE

The camera has no IR filters and can easily pick up IR from other sources etc.

This is pretty much the camera...don;t seem to have the exact model anymore.

Mark

E-bay is swamped with ultr-bright LED's. I'm sure i've seen IR Leds amongst the ad's.

Use the LED's out of old remote controls. Some of the better, newer ones put out a considerable amount of IR light. Thrift stores are a good, cheap source.

the responsivity of the ccd will likely fall off, the higher the wavelength.

You will likely want to go with a lower wavelength. THis will help keep your sensitivity up. Human vision essentially falls off at 780 nm.

One way to increase the brightness of the LEDs is to pulse them - keeping the average current ~30mA, you can push the peak current up. Sync the pulses so the LEDs are on only when the imager is integrating and off otherwise.

I haven't tried this before, but perhaps you could also try using a halogen torch light (with reflector etc) and filter away the visible light. Fully exposed 35mm film works pretty well as an IR filter if you need a cheap source.

Kevin

I'm not sure if this is any use, but I had a Sony vid cam with nightshot, and I seem to recall that you could buy an external light for them. I know even with just the regular IR, you could see 20-40' depending on light interference.