h a l f b a k e r yInexact change.
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I was wondering though, what if you just had a
little pinhole, i.e. teeny tiny camera, which
scanned your body for heat? Would that make it
cheaper? There are heat-sensitive liquid crystals,
after all. Could temperature be measured by
passing light through a layer of heat-sensitive
liquid crystal?
Edit: It does indeed look, er,
"cool" (probably should find a word) but no price
visible from here implies high price i think. Either
that or that i live in Europe and they can't sell me
it. |
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Couldn't you get clever with ordinary pyroelectric motion detectors and some IR filters?
Maybe a spinning prism, and make yourself a simple thermal imager. |
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Maybe. What i'm trying to work out is what makes
the normal cameras so expensive. That looks like
it'd work, but would it be cheaper? Is it a
question merely of economies of scale? |
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[+] nice idea; however I suspect that all you need is the overall IR figure - the actual distribution is probably not important. If you are letting out heat, it doesn't really matter where it is escaping. That would really cut down the costs involved. (I personally find that stepping out of the door quickly tells me if I am under-wrapped for the cold). |
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//what makes the normal cameras so expensive//
Germanium optics? |
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Hah! You've just shown why the hotties in the old sci-fi flicks always wore aluminum foil! |
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Yes, that'd be really good.
[coprocephalus], i read earlier that something can be done with silicon, but since i don't know how they work anyway, that doesn't help.
On poking about a bit, it looks like the reason it can be expensive is that the sensors have to be cooled cryogenically. There's a new cheaper method using something called a microbolometer, which doesn't need cooling.
[vvv], i think it might matter where. For instance, i'd prefer my feet to be cold than my hands. |
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All CCDs see in the infrared, so I think all you'd need is a large IR focused lens covered by a IR filter and you'd be off to the races. A couple of years ago I think Sony came out with a nightvision camcorder and there was a huge hubub (sp.?) about the ability of the camera to see really well in IR. To the point of being able to see the shape of the body thru clothes. It wasn't X-ray specs but good enough to sell out IR filters and that model of camcorder all across America. |
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//All CCDs see in the infrared// Only the near infrared; they don't detect wavelengths as long as those produsec by body heat. |
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[21 Quest], i see you've done that and it doesn't bother me in the slightest. That's fine. We all collaborate on here after all, don't we? |
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