next topic »

[on:]

Hello,

I'd like some input on the feasibility of building an infrared laser spotlight using and X-Y scanning beam (moved by servo motors or whatever) and having the reflected IR detected by goggles, or a webcam (which I believe is sensitive to various IR frequencies).

This would be a  night vision system, invisible to others, to be used for hunting feral animals or just seeing if anyone is roaming around my property.

Has this been done before ? Would it be practical ?

thanks,

hsteve

[Reply #1 on:]

The problem with scanning a laser is that you would have to scan very quickly so you would need a galvanometer scanner. You might also have to synchronize with the camera.

Most people just use a bunch of high-power IR LEDs.

[Reply #2 on:]

What sort of range do you get out of high power leds ?

[Reply #3 on:]

What sort of range do you get out of high power leds ?

Like many things, it's as much as you are willing to pay for.  It will depend on the sensitivity of your camera and the power of the LEDs.  You can add more LEDs but you will then need to cary more power to feed the LEDs.

This $40, 6 Watt unit claims '60 foot range': http://www.bhphotovideo.com/bnh/controller/home?is=REG&Q=&A=details&O=productlist&sku=563919

[Reply #4 on:]

Please remember that you have  no blink reflex to IR, and you could cause eye damage very easily.
Even some uncollimated IR sources like traffic camera illuminators have eye-safe distances of five or more metres.

[Reply #5 on:]

Back in my Airsoft-playing days, most if not all sites I played at where night games were organised had an outright ban on IR lasers (presumably for use with Gen1 night vision gear) as they were not considered "eye safe". I'd go with LEDs and just keep adding more until you achieve the desired effect

[Reply #6 on:]

I'd go with LEDs

What I was saying was even uncollimated LED arrays can be dangerous.
Please be careful

[Reply #7 on:]

Good advice, thank you.

[Reply #8 on:]

I suppose the alternative is a passive system like this

http://www.cheap-thermocam.tk/

,but it takes a few minutes to create an image.

Are there any ways this could be made faster ?

[Reply #9 on:]

Are there any ways this could be made faster ?

You could use more thermal sensors but at $45 each that gets expensive quickly.

[Reply #10 on:]

Sorry to carry on with this, but are IR phototransistors responsive to IR emitted by humans & animals, and would they be suitable as detectors for the project I have in mind ?

[Reply #11 on:]

but are IR phototransistors responsive to IR emitted by humans & animals,

No, they are not, and no, they wouldn't.

[Reply #12 on:]

OK, I've ordered one of these

http://www.freetronics.com/pages/irtemp-infra-red-temperature-sensor-quickstart-guide#.USsn9TfBYrU

and I'll muck about with it for a while

thanks for your patience & responses