From:	David Woods <david@*******.FREESERVE.CO.UK>
Subject:	Re: thermographic vision-question
Date:	Tue, 2 Feb 1999 21:19:20 +0000

Jester wrote:
>
> O.K. Surely you guys/and gals on this list, can help me. I have this
> player in the group who sees thermographic vision as the ultimate
> solution to perception tests. He states that with thermographic
> vision you can see nearly (through) everything.

No. Your player is assuming the crap Hollywood version of IR (i.e.
Predator I and II). Assume any solid object (including glass) is opaque
to IR.

If you can see through everything you can't see anything!

Very thin plastics sheets like bin-liners are quite transperent and so
are some *very* expensive materials used to make lenses for IR cameras.
So if you find a window that you can see though with Thermographic
Vision, steal it.

> I think he's
> mistaking it for IR-vision, but I can't get that in his head.

Thermographic vision is IR vision.

> Could someone please post a mail explaining what thermographic vision
> is, and how it works. Preferably long, with lot's of difficult words
> in it (his English isn't that good:)).

Thermographic vision allows you to see temperature differences. A person
is generally warmer than his surroundings and so he will appear as a hot
shape against a cold background.

In SR this ability is very precise, so very small temperature changes
will be seen. This allows for a good perception of the surroundings,
although not as good as normal vision. Thermographic vision is in fact
more limited than normal vision; reading number plates for instance
would be impossible or at least very difficult. Recognising faces would
also be impossible/v.difficult.

Different materials give out different IR profiles. So two different
materials at the same temperature should be distinguishable if the
vision was good enough. A lizard on a rock might be seen by a Dwarf, but
a Sammy with the Cyber version might miss it.

Basically Thermographic Vision is nice in the dark, but normal vision is
visually superior.

Regards

- David Woods