Re: IR filters

[Wolff <wolff_b@ix.netcom.com>]

You are talking about a "cold" mirror. Works exactly backwards from your
idea. They look silver like a regular mirror, except that you can see a
little red through them. They are used in high intensity lamphouses. The
visible spectrum is reflected off the mirror to a useable location while
the IR is thrown away straight through the mirror. You simply want to
reverse what is "kept" or used. These baby's do cost though. I think a
4" square is about $200. They can take a lot of heat. I have gotten
burned off of them when changing lamps. Imagine a 1000 watt lamp about
1" away from it. That's bright.
Wolff

<snip>
> 
> A more elegant solution (any geniuses out there?) would be a dichroic
> mirror that would reflect only IR. The rest of the bulb's energy could
> be directed into an air-cooled baffle box. The mirror would not have
> the fading problems a filter will sufer from.
> 
snip