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Artem vs. Predator

ribbonfarm.com

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Re: Artem vs. Predator

#61

Post by JonathonW »

SamBam wrote: post #57

Forgive my ignorance, but if this system would require liquid nitrogen cooling to detect heat from a human, how do commercial (now almost cheap) thermal cameras work? Are they not sensing IR? The can certainly distinguish the different temperatures of different people, without needing to be cooled themselves. How is this system better than a commercial IR camera -- besides the very obvious and valid reason that this…

As I understand it, uncooled commercial IR cameras aren't photodetector-based: their sensors are actually heat-sensitive and rely on heating from IR to produce an image. This limits sensitivity and resolution and increases noise.

Higher-quality IR imaging equipment is photodetector based (as in, they operate on the photoelectric effect); these require very low temperatures to operate and need the sort of active cooling the author refers to.

See also https://en.wikipedia.org/wiki/Thermographic_camera , which goes into detail on the different technologies involved.

Re: Artem vs. Predator

#62

Post by DanBC »

adrianN wrote: post #27
paulgerhardt wrote: post #21

Infrared film used to be available commercially with sensitivity up to 900nm. It was quite useful for aerial photography work – forestry, surveying, spying. Very little of it is still around. Kodak Ektachrome was what one could get for your high school dark room. Aerochrome for surveying work. It was discontinued in 2009. Ilford however still makes some. Be forwarned, finding someone to develop the stuff is a nightma…

Do you have do develop those films in the freezer? A normal dark room is not really dark at those wavelengths, even if you turn the red lamps off, right?

Home processing of some regular B&W infrared film was tricky because the small tanks would sometimes be giving off IR, and would fog the film.

Re: Artem vs. Predator

#63

Post by StavrosK »

knowaveragejoe wrote: post #52
StavrosK wrote: post #45

Earlier quoted context omitted.

Just star trails, probably: https://upload.wikimedia.org/wikipedia/commons/f/f8/Star_tra...

Yes, but distorted because of the way the sensor is also moving.

Ah, interesting. They'll be discontinuous dots along that line, true.

Re: Artem vs. Predator

#64

Post by alphapapa »

keyme wrote: post #29
alphapapa wrote: post #20

So is the future wavelength project something like radio waves? It would be fascinating to see an image lit by radio waves. Imagine a wifi router being lit up like a lightbulb, casting shadows around a room, or a room lit by FM radio passing through walls and windows, etc.

Walls are transparent to FM (~100MHz) radio, so you won't see anything. WiFi is closer. High microwave is probably what you want here. And of course, this already exists. It's called radar. Haven't seen any radar "photos" though. Interesting if that's indeed possible.

> And of course, this already exists. It's called radar. Haven't seen any radar "photos" though. Interesting if that's indeed possible.

Oh, right, synthetic aperture radar. Duh. Should have thought of that. :)

Re: Artem vs. Predator

#65

Post by elcritch »

Artlav wrote: post #43
gregorkas wrote: post #12

You know those black and white photos? I thought Russia looked like that with regular cameras :P. Just kidding, this has to be one of the coolest projects I've ever seen. To make all this by yourself is just ... awesome.

Here is one of the more apocalyptical ones (i call it "The storm is coming"): http://i.imgur.com/zFD4znl.jpg

Eerily similar to the clouds in the original Doom! Luckily real Russia is only partly apocalyptic looking... Though I'm from Wyoming which boasts our own post-apocalyptic scenes. ;)

Re: Artem vs. Predator

#66

Post by elcritch »

Artlav wrote: post #41
monk_e_boy wrote: post #16

I assume the distortions at the edge of the 'photos' is due to the X Y scanning rig. Moving the sensor around the edge of a sphere (on a curved X Y (and a little bit of Z) rig, the focal point being the center of the sphere) would sort that right out. I expect the 3D printer could make a curved rail for the rig. Or you could point the sensor at the center of the pin hole or lens using a mechanical linkage, then use s…

About half of the pictures in the article are taken with the lens assembly. Pinhole is good for outdoors and sunshine, but is useless for MWIR/SWIR and indoors scenes, even with my 600W Metal Halide lights. The lenses give the radial blur at the edges effect, pinhole gives the darkening at the edges effect.

I am intrigued by your ideas and would like to subscribe to your newsletter... Joking aside interesting projects! Could you send me an email? Perhaps I can convince you to do some consulting work. Haha, the world needs more predator vision! Though ya née gavayete pa Ruski.

Re: Artem vs. Predator

#68

Post by Terr_ »

> Heat vision. [...] MWIR is neither heat, nor is it light. It’s both

No, it isn't. The "infrared light is heat" statement is casually-useful but technically-false, which means it backfires and harms people when they start learning more about physics.

IR radiation is not the intrinsic heat-content of the matter emitting it. Infrared is simply a particular set of wavelengths which happens to be prominent for temperatures which are "hot" for us just because we evolved on this small rocky planet which has a certain baseline temperature.

Go ask some icy crystalline aliens or ones powered by low-grade nuclear reactions what they think about "heat radiation" and you won't get the same answer.

Re: Artem vs. Predator

#69

Post by Artlav »

elcritch wrote: post #66
Artlav wrote: post #41

Earlier quoted context omitted.

About half of the pictures in the article are taken with the lens assembly. Pinhole is good for outdoors and sunshine, but is useless for MWIR/SWIR and indoors scenes, even with my 600W Metal Halide lights. The lenses give the radial blur at the edges effect, pinhole gives the darkening at the edges effect.

I am intrigued by your ideas and would like to subscribe to your newsletter... Joking aside interesting projects! Could you send me an email? Perhaps I can convince you to do some consulting work. Haha, the world needs more predator vision! Though ya née gavayete pa Ruski.

Newsletter might be too big of a word, but i do publish various stuff i work on at http://orbides.org/

You can also find the e-mail over there in the bottom-right corner.

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