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Old 04-02-2017, 01:49 PM   #40
Join Date: Jun 2005
Default Re: [Basic] Advantage of the Week (#38): Dark Vision, Night Vision

Originally Posted by Flyndaran View Post
Reptiles are faint in modern low res mediocre thermal vision, but they're still detectable, from what I've seen of such videos.
Gurps Thermal vision is as discerning as base line vision, so they're much better than anything we have now.
If you mean "Infravision," I don't recommend using it if you're trying for a scientifically or technologically accurate model of how such things work. The GURPS notion of Infravision, like those in many other games, lumps all wavelengths of "infrared" together and gives them properties that derive partly from thermal infrared and partly from near infrared. I had some trouble sorting them out in Enhanced Senses.

Thermal infrared is what things like bolometers detect. It doesn't allow good image resolution; on the other hand, animals and indeed common inanimate objects emit in that band, so you can see them even without a light source. Near infrared, in contrast, allows much better resolution, and I believe it's what things like "night vision" systems detect—but there's almost none of it being emitted after the sun sets; you start getting a dull glow at 350°F. I believe that a common configuration is to have a light source whose visible light output is block, so that it emits NIR, which is then reflected off of objects and allows imaging them much like imaging with visible light.

I'm not entirely sure which type of system you're describing; if reptiles emit a modest glow, it's probably thermal IR. I'm pretty sure that technological "night vision" systems work with NIR emitters and detectors, and at those wavelengths, neither reptiles nor mammals emit at a significant level, any more that either species has a visible glow from its body heat.
Bill Stoddard

A human being should know how to live fast, die young, and leave a beautiful corpse. Specialization is for insects.
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