From: Mike Poulton
Subject: Re: Make infrared goggles inexpensively (like $10!!!)
Date: 16 Sep 2002 19:50:14 GMT
Organization: MTP Technologies
References: <firstname.lastname@example.org> <4Aoh9.15391$1C2.email@example.com>
On 16 Sep 2002, "Tom Del Rosso" said:
> "William J. Beaty" wrote in
> message news:firstname.lastname@example.org...
>> New article just added, check it out:
>> Make your own passive IR filter-goggles
>> Human eyes can see IR light if it's very bright. Sunny days
>> have quite a bit of IR in them.
> Whether or not you are really seeing the IR, it is certainly true that
> a lot of IR is entering your open pupils. I think more consideration
> for safety is needed before I would try it.
> If the sky is almost black, then what happens if you gaze around and
> your eyes unexpectedly find the sun?
At 1mW/cm^2 full spectrum, the sun is not that much of a hazard to
vision. Once you cut out all the visible and UV light, you're left with
a small fraction of the original irradiance in the near IR. Since brief
glances of the sun without a filter aren't too damaging, brief glances
with the filter can't be very bad, even if your pupils are a bit bigger.
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