
Artem vs. Predator - sharpn
http://www.ribbonfarm.com/2016/05/12/artem-vs-predator/
======
micheljansen
A cool property of NIR filters is that they are able to produce a relatively
recognisable picture of the world with all screens (TFT, projected) filtered
out. I've used this in the past for computer vision to do object recognition
on top of a projected display without having to programmatically filter out
the projection.

It's also pretty easy to make a rudimentary NIR filter by layering a red,
green and blue filter on top of each other: the resulting filter will not
allow any visible light through (e.g. red, green or blue), only the "rest".

edit: and they make your eyes look really creepy too (not me in the picture
btw): [https://flic.kr/p/6CYzDZ](https://flic.kr/p/6CYzDZ)

~~~
Artlav
Another easy way to make a NIR filter is to get a couple of black frames of a
regular photographic film - it's transparent to NIR, but blocks all the
visible light.

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monk_e_boy
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 some software to warp the resulting image.

~~~
d--b
No it's a property of pinhole diffraction:
[https://en.wikipedia.org/wiki/Airy_disk](https://en.wikipedia.org/wiki/Airy_disk)

~~~
monk_e_boy
The buildings at the edge of the photos look warped. Like an extreme fisheye
lens would do.

Airy disk affects brightness and sharpness, not warping.

You could put a camera lens where the pin hole is to negate this warping, but
that defeats the point of a pin hold camera.

~~~
cma
Yes, it is proably more petzval field curvature than diffraction limiting:
[https://en.wikipedia.org/wiki/Petzval_field_curvature](https://en.wikipedia.org/wiki/Petzval_field_curvature)

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dharma1
Not just heat, there is a lot of interesting spectral data we don't see.
Hyperspectral cameras are rare and expensive right now - but I'm really
looking forward to the day they are cheap and commonplace

[https://www.youtube.com/watch?v=OcAstSnbVX4](https://www.youtube.com/watch?v=OcAstSnbVX4)

[http://www.specim.fi/](http://www.specim.fi/)

[https://www.ximea.com/](https://www.ximea.com/)

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SamBam
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 is DIY, and started long before those were
cheap?

> _" The most amazing part is not that it glows, but that it glows brightly
> enough to illuminate the stand. It’s not just the “temperature mapped to an
> image” of a regular heat vision camera, we see the actual long-wave light
> being emitted and reflected – a soldering iron turned into a lightbulb!"_

How is that different from this image, which shows a duck's IR being reflected
by water, made by a cheap-o "regular heat vision camera"? [http://thermal-
imaging-blog.com/wp-content/uploads/2012/05/d...](http://thermal-imaging-
blog.com/wp-content/uploads/2012/05/ducks-22.jpg)

~~~
JonathonW
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](https://en.wikipedia.org/wiki/Thermographic_camera)
, which goes into detail on the different technologies involved.

------
gregorkas
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.

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

~~~
elcritch
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. ;)

------
sbierwagen

      This was my first encounter with ITAR – the “how dare you 
      want interesting stuff?” restrictions. Before then I 
      never realized just how USA, uh…, loves the whole world.
    

ITAR is a US regulation, and the USA doesn't have jurisdiction on a sale from
a Japanese vendor to a Russian customer. You're thinking of MTCR, "an informal
and voluntary partnership" between 34 countries. Both Russia and Japan are
members:
[https://en.wikipedia.org/wiki/Missile_Technology_Control_Reg...](https://en.wikipedia.org/wiki/Missile_Technology_Control_Regime)

------
dmvaldman
"..when I started there were no 3D printers. Eventually I made one, and all
the clumsiness of the old rig got replaced with modern, 3D printed, well-
fitted parts."

When I read this I thought, "nah"... but some digging later and

[http://orbides.org/page.php?id=703&lng=eng](http://orbides.org/page.php?id=703&lng=eng)

~~~
fudged71
I've seen a lot of hacky DIY 3D printers, but this is the roughest. Love it!

------
taneq
Great read! I'm curious about the last bit, saying you need liquid nitrogen
cooling to detect the radiated heat from a human. I'd always thought some
snakes have infrared-sensitive spots near their mouths that could sense
mammals from a distance, are they just that much more sensitive than a
photodiode? Or are they sensing something else?

~~~
venomsnake
Snakes are seeing in the closest to visible specter IR IIRC. Also they have
evolved a lot of other sensory mechanisms to detect pray - sounds, vibrations,
taste

~~~
adrianN
[https://en.wikipedia.org/wiki/Infrared_sensing_in_snakes](https://en.wikipedia.org/wiki/Infrared_sensing_in_snakes)

They can sense radiation between 5 micrometers and 30 micrometers.

~~~
taneq
Wow, so instead of a photochemical or photoelectric effect, it's actually
literally a heat sensor - as in, radiation from the environment heats the
interior of the heat pit (which is cooled by the snake's blood to maintain a
baseline) and it is this change in temperature that is detected?

I wonder if the ribbonfarm guy could use a variant of this for his pixel
scanner thing?

~~~
ambicapter
That is the operating principle of a bolometer.

------
fitzwatermellow
Nice way to start the day ;) Can't someone send this guy a box of gently used
CCDs and some wideband lenses already or maybe an old copy of labview...

Oh and Artem, if you happen to see this, can you try getting out of the city
on a cloudless night and taking a long exposure of the night sky? Thanks for
your hard work and inspiring us all!

~~~
Artlav
Artem here, that's a strange idea. Right now the sensor got a fixed gain, and
so exposure time is meaningless. It won't be too hard to add, but what sort of
image would there be, with the frame time of many hours, line by line as the
planet rotates? Sounds curious enough to try. :) I anticipate a distorted
starfield - every star as a bright point, but all of them shifted in position.

~~~
StavrosK
Just star trails, probably:

[https://upload.wikimedia.org/wikipedia/commons/f/f8/Star_tra...](https://upload.wikimedia.org/wikipedia/commons/f/f8/Star_trails_over_the_ESO_3.6-metre_telescope.jpg)

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

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

------
alphapapa
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.

~~~
keyme
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.

~~~
jakobegger
The size of the things you can see depends on the wavelength of the light.

FM Radio (100MHz) has 3m wavelength. You'll need a giant camera and will be
able to see only very big structures.

Wifi/Microwave/Radar is in the Gigahertz range. 2.5GHz == 12cm wavelength. For
radar photos, you'll need a very big camera, and a human would be only a few
pixels big.

Some airport scanners are based on millimeter waves (teraherz radiation), and
you can find sample photos online. They produce pretty blurry pictures, but
clothes become partially transparent.

------
sangnoir
> But for our goal it’s important to remember, because infrared light does not
> pass through glass

I thought that was UV?! If that statement is true, how on earth am I able to
busk in the heat of the sun behind a glass window, indoors?

~~~
adrianN
The sun produces visible light as well.

~~~
panic
Yes, I think this is a common misconception: infrared light is "heat
radiation" in the sense that it's emitted from hot things, but any wavelength
of light you absorb (not just IR) will heat you up.

~~~
sangnoir
> but any wavelength of light you absorb (not just IR) will heat you up

Thanks - this is the bit I was un-/miseducated about. When we were taught
about radiation in high school, I suspect my young mind concluded that since
infrared and visible light were mutually exclusive on visibility, the same
applied to heating. To this day, I thought infrared → heat _and_ heat →
infrared.

~~~
AnkhMorporkian
I just happens that at everyday temperatures familiar to humans, the primary
wavelengths emitted are infrared. Heat something enough, and that curve will
shift to predominantly visible wavelengths; think about an electric oven.

------
paulgerhardt
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 nightmare, the chemicals are toxic, and the shelf-life
brief.

Scientific infrared films, such as special formulations of AeroChrome I, II,
II, approached sensitivity up to 1200nm.

In surveillance work, objects which were painted to look like their natural
environment using various organic or inorganic paints may show up quite
differently in the infrared spectrum.

In forestry work, old growth tree populations could easily be distinguished
from new growth tree populations and were one of the primary uses for Nasa's
version of the U2 (ER-2) for identifying old-growth redwood populations in
northern California. [1]

A lot of work was done in the 1970's and '80's by astronomers and physicists
to 'hack' Eastman Kodak scientific film, or plates as they were called. (Once
you move past "point and shoot" film, you get into the realm of plates, 4"x5"
trays similar to old-timey 1880's cameras.) Things like Kodak I-Z. One
technique was to hypersensitize the film by bathing it in Ammonium Hydroxide
[2]. Lawrence Livermore had such an appetite for IR-sensitive film with their
laser work that they set up their own production process for hypsersentizing
Kodak scientific plates. Another was to supersensitize them with acetic
solutions getting film sensitivity in the >1500nm range [3]. This seems to be
the limit of our knowledge for traditional chemical film processes.

Modern DSLR's have sensitivity up to 1600nm. Nikon worked with NASA for some
of their special DSLR's [4].

One of the cooler things I saw was a University of Florida paper in Nature
that used IR-OLED's to upconvert IR to visible light through a lens adapter
achieving sensitivity from 400nm to 2000nm [5].

Beyond 2000nm you get into the MWIR range and FLIR devices take over.

[1]
[https://books.google.com/books?id=HZUTCgAAQBAJ&pg=PT129&lpg=...](https://books.google.com/books?id=HZUTCgAAQBAJ&pg=PT129&lpg=PT129&dq=u2+spy+plane+infrared+film&source=bl&ots=rxHraY2iqm&sig=e45ipoJHIIsy4D_huZVk3MKwBRw&hl=en&sa=X&ved=0ahUKEwi_2q-a09bMAhUO_mMKHVPTA4wQ6AEIHDAA#v=onepage&q=u2%20spy%20plane%20infrared%20film&f=false)

[2]
[http://www.osti.gov/scitech/servlets/purl/4442636/](http://www.osti.gov/scitech/servlets/purl/4442636/)

[3]
[https://books.google.com/books?id=nlftCAAAQBAJ&pg=PA259&lpg=...](https://books.google.com/books?id=nlftCAAAQBAJ&pg=PA259&lpg=PA259&dq=spectral+sensitization+for+i-1060v-2&source=bl&ots=pNFdp7EB9s&sig=qPC3JdbftREwOsDNtDLc5msnj-o&hl=en&sa=X&ved=0ahUKEwiLzfb55dbMAhVS7mMKHVGaB9IQ6AEIHDAA#v=onepage&q=spectral%20sensitization%20for%20i-1060v-2&f=false)

[4]
[http://eol.jsc.nasa.gov/Collections/NearIR/IR_Intro.htm](http://eol.jsc.nasa.gov/Collections/NearIR/IR_Intro.htm)

[5]
[http://www.nature.com/articles/srep05946](http://www.nature.com/articles/srep05946)

~~~
adrianN
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?

~~~
falcolas
Former B&W technician: All film is developed in complete darkness; it it
sensitive to all wavelengths. The B&W photo paper is not sensitive to red,
which is what allows you to have a dim red light on while printing
enlargements.

And yes, it takes time to learn to navigate the room and work in pitch
blackness. Gave me a lot of respect for the blind. At school, we could develop
one roll at a time, allowing for the use of small containers which would let
you work within a dark bag for a small period of time. At the photo shop, they
had a machine for processing film in batches of 10+, which required the entire
room to be dark while loading it.

Modern film processors frequently don't even require the dark box (unless the
film canister is in really bad shape) - just stick it in, close the door, push
a button. Remarkably slick.

------
stared
It is possible to see in near infrared - just use a IR filter (used for
photography), and stick it to your eye. Everything should look dim and
reddish, but what is characteristic (and different from a red filter) is that
leaves are very bright. Also, many black t-shirts are not-dark.

Also, it's fun to make such photos:

[http://migdal.zenfolio.com/ir-old](http://migdal.zenfolio.com/ir-old)

~~~
david-given
Just be really, really careful about sunlight! When you're using a filter like
this your iris is wide open, and exposure to direct sunlight or _reflected_
direct sunlight can damage your eyes.

~~~
alphapapa
Yes, probably the most comprehensive site about making and using IR goggles is
here:

[http://amasci.com/amateur/irgoggl.html](http://amasci.com/amateur/irgoggl.html)

He has some very interesting photos taken with them. He also cautions about
the iris being opened wide when wearing them, although he claims that he's
suffered no ill effects after using them for years (avoiding looking at the
sun, of course).

------
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.

------
spatular
Have you tried zone plates instead of lenses? Feature sizes should be larger
for IR than for visible light, so it's should be possible to fit enough zones
to get some focusing.

~~~
spatular
To expand a bit on construction: it's possible to take a long tube, put a
fresnel lens at front, pyroelectric sensor with rotating shutter at the other
end. Scan by rotating it with reductors/steppers as a whole. It's also
possible to cool tube with contents down to -70 with dry ice to cut on
background heat radiation. Maybe it'll lessen noise in pyroelectric sensor,
maybe not (and it's quite easy to buy dry ice in Moscow).

------
aavotins
Incredible dedication and a fantastic project. I wonder if a setup made from a
FLiR Dev Kit, a Raspberry Pi and the Pi camera would produce similar result?

------
ivanb
This guy is spectacular. Check out his other work:
[http://orbides.org/](http://orbides.org/) Here is a nice concept of an
interstellar ship
[http://orbides.org/concepts.php?lng=eng](http://orbides.org/concepts.php?lng=eng)

------
haddr
Cool stuff!

I think that regarding the near infrared light a regular CCD element could be
useful as well, as those are sensitive to infrared too. The only problem is to
filter the visible light to leave the infrared spectrum only. Also be sure
that the ccd doesn't have a IR filter (some does).

------
IamFermat
For 21st century Predator vision, this is the closest to it. Thermal IR from
FLIR -
[https://www.youtube.com/watch?v=L7URETAl75A](https://www.youtube.com/watch?v=L7URETAl75A).
Someone should hack this into a pair of glasses.

------
t_fatus
Never Give Up.. This should have take SOOOOO long, with so many disaopointment
! Really nice job

~~~
clort
I got the feeling this did take a long time, he mentions things becoming
available, and technology changing.

"This project spans years, and when I started there were no 3D printers.
Eventually I made one"

------
ck2
People who dig to understand and create stuff like this are just amazing.

------
vvanders
Now that's real engineering.

------
muloka
This was a fascinating read. Thanks for sharing.

------
ommunist
Great read. Tireless enhancements until goal achieved. Great job.

------
mmastrac
This is a great story, but the original title of "Artem vs. Predator" is much
better than the submitted one.

~~~
Houshalter
The title is artem v predator, but gives zero information of the content. I
clicked out of curiosity but usually avoid vague titled links.

~~~
igravious
I didn't click on this for ages because the title contained not a clue that
this was such a cool multi-year exploration of infra-red radiation. I only
clicked eventually because it stayed on HN front-page for so long.

