I never knew this...

[Karlos]

that_punk_guy wrote:

When I enquired at the electronics shop a few months ago the guy behind the counter suggested that the cost would be prohibitive if I wanted to flood a room with infra red light. May have a nosy on the web.

How about making a grid array of super bright IR LED's - the kind you can pick up for a few pence a piece. I'm sure you can illuminate a decent area with those. I have some ordinary super bright red led's (years old now) that are 5000mCd brightness - a few together is like a torch beam. A decent grid of IR ones of a similar output would be like an IR floodlight :-D

[Karlos]

@Vincent,

He was coming back for the money but by then they'd seen his face, getaway car...

[Karlos]

'lo

that_punk_guy wrote:

Dan wrote:
I wonder how one of those heatlamps, used for piglets and chickens would work as an source of IR-light?
200 or 300W it would light a bigger area than a diode
but then again they give of visible (red) light also

You could install them behind filters, in fact I think it's been done (going by what the guy at Emery's told me) but it sounds awfully inefficient.

There's IR and there's IR. Thermal radiation is typically a longer wavelength than that used in IR applications. The latter is really not far beyond the visible spectrum - 650nm or so IIRC (aka near IR).

I don't think the CCD's in normal cameras etc are receptive to "thermal" IR. Unless your webcam sees a hot cup of coffee as a light source, that is ;-)