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Originally Posted by whswhs
You've got those terms reversed.
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Whoops, so I do.
Quote:
Originally Posted by whswhs
Realistically, infrared vision that responds to human body temperature has poor resolution; the wavelength of peak emission at human body temperature is about 16x that of monochromatic green light at peak human visual sensitivity, and for an eye of a given size, resolution is limited by wavelength. So you'd get around 20:320 visual acuity at best.
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Well, a bit better -- 20:20 vision requires a pupil size of around 4,000 wavelengths, which is 1.6-2.8mm for the visual spectrum, and probably around 35mm for a reasonable thermograph, so a pupil dilated to 7mm might approach 20:100.
Quote:
Originally Posted by whswhs
You can do a lot better with near infrared, which could get you to around 20:40, but NIR emission from a human body is nearly zero; you'd need a temperature of around 4000°F to get peak emission in the NIR, if I'm figuring Wien's law right.
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True, though you don't need peak emissions to detect something (last I looked at this, I figured NIR might reduce darkness penalties for total from -10 to -9). Mostly what NIR will give you is a modest bonus to night vision when the primary light source is incandescent, and a larger bonus when it's something like a candle or torch.