Infrared Webcam HOWTO

Geoff Johnson writes "Some of the Slashdot readers may be interested in this page I put together. It describes how to make an ordinary webcam see in the near infrared waveband."

Comments

duh

[oliverthered]

Let me guess, remove the IR filter from in-front of the lens.

Re:duh

[m50d]

Well, and replace it with one to block visible light. But yes, that's about it.

Re:duh

[oliverthered]

You don't need to for 'night vision', which is what I expect most people will be interested in.
Full colour (maybe a tiny bit washed out because of the extra IR) during daylight, and at night switch on the IR light and you've got an IR camera.

Near IR isn't that interesting, except humans cant see it, what would be cool is if the chips could pickup far IR so you could see heat.

Re:duh

[budgenator]

Cadillac has an interesting thermal system, I haven't really dug into it in depth, but basicaly the sensor is a bunch of capacitors similar to a ccd sensor. When the IR image is focased on the sensor, the heat causes the diaelectric between the capacitor plates to warm up and expand changing the charge on the capacitor and make it readable.

Sooner or later someone is going to hack the system for some serious geek factor. I could see someone hackering several of these different systems together for some cool false-color IR video. I used to do quite a bit of IR photography used Kodak's IR false-color slide film, green showed up as blue, red was green and IR was red if memory serves me correctly. The biggest problem was the film used the old-fassioned E4 process, so you either had to send it to Kodak or do it your self

Re:duh

[oliverthered]

Lots of things work, you can easily buy a IR pass filter.

I I've used purple sweet wrappers in an IR remote control, and often the plastic in the housing is good enough to block most visible light but pass IR.

Re:duh

[huge colin]

Cadillac's system was actually a Barium Strontium Titanate (BST) module, developed by Raytheon. It required a thermal differential in the scene from frame-to-frame to be able to see anything, and thus a "chopper" wheel (a rotating slotted disc) had to run in front of the detector. The picture would smear and was generally low-quality. The module used by Cadillac was also rather low resolution (160x120, I believe).

The alternative to BST is microbolometer technology, developed by Lockheed Martin / BAE Systems and others. A microbolometer array consists of vanadium-oxide bridges that vary their resistance when exposed to thermal radiation. The scene will occasionally need to be "shuttered" (i.e., zero all the pixels against the back of a shutter mechanism to cancel the thermal drift that creeps in over time.)

Unlike light-amp, true thermal imaging allows you to see in complete darkness. And unlike projected-IR, it isn't limited in range by any kind of IR-transmitter. And unlike either of those technologies, it allows you to very quickly find humans (or other mammals) in a scene, and it allows you to see where things used to be by the heat-shadow that they've left.

Re:duh

[budgenator]

basicaly the E4 process you expose the film

1. develope it the reduce the exposed silver halide crystals to metalic silver( results in an negative image)
2. bleach out the exposed silver( removes the negative image)
3. remove the film and expose it to light which exposes the undeveloped silver halide crystals
4. re-develope the film to reduce the exposed remaining silver halide crystals to metalic silver resulting in an positive image
5. fix the film to remove any undevelopes silver halide crystals
6. the silver reacts with the dyes in the film to become visible as color pixels

this results in a postive image or projection slide. The false color means the colors on the film don't represent reality.

Oh, great.

[millennial]

Now Paris Hilton's new sex tapes will be done by webcam... meaning even worse video quality! Seriously, though, that's pretty sweet. Props to this guy for figuring out how to do it.

Re:Oh, great.

[Xyrus]

This isn't really anything new. Amateur astronomers have been doing this with webcams for awhile now. Even in the near IR range, some things look a little different.

Not recommended when planet imaging.

~X~

Can it see through clothing?

[Anonymous Coward]

Cause I'd really like to take my PC to the beach and get webcam shots of da honey's.

Re:Can it see through clothing?

[rbarreira]

The important question is... Can one do some glasses which work like that? ;)

Re:Can it see through clothing?

[Anonymous Coward]

Im sure they wouldn't find anything suspisous about a guy with a laptop with webcam attatched.

Re:Can it see through clothing?

[anagama]

This was covered on slashdot a long time agao.

But yes, it can see through clothing to some extent.

Re:Can it see through clothing?

[mp3phish]

Time to start wearing some tin foil braws!!!!

(and panties :)

infrared wecam!

[Anonymous Coward]

that's just fantatic!

Night Vision Linux Webcams All the Rage?

[filmmaker]

Infared web cam? Somehow I don't think Bubble Cam would be quite the same at night. :D

I do wonder what the most common applications for Linux/IrDA are, considering the trend I've observed where among the most commonly requested Linux HOWTOs recently have been 'laptop', 'infrared' and 'webcam'. Is everyone building infrared webcams?

cached link of video if it dies.

[Organized Konfusion]

http://homepage.ntlworld.com.nyud.net:8090/geoff.j ohnson2/2004-08-08.avi

Re:Infrared

[AndroidCat]

Have you tried a universal remote that supports dog? It the pause button works then you need to talk to the patent lawyers.

The WEcam...

[mindriot]

...and, soon to come, the THEMcam!

SCNR... sometimes I'm amazed at what kinds of typos make it through to the frontpage.

But besides that, very nice article. I personally found IR very useful for some surveillance-type situations. A few years ago, my father set up an IR-sensitive camera and an IR diode in a birdhouse in our garden, which allowed us to watch the new-born ones without creating any disturbance.

Burgler Cam??

[GreyPoopon]

Does anybody think that coupled with a pure IR source of light this item would be useful in catching would-be prowlers without alerting them? OK, probably a stupid idea...

Re:Burgler Cam??

[shic]

There is a lot more to the idea of video security than the simple "alerting" or "non-alerting" you suggest.

For example, using your example of a car - I'd consider myself a madman if I opted not only to have a car alarm - but also to make it as obvious as possible that I am equipped with one. The snag, however with alerting alarms is that after a few "false alarms" it is widely understood that alarms signals will be ignored - people assume it is a technical fault... and the criminals know this too. Another problem with the alerting alarm is in automatically deciding at what point to take issue with someone's actions. For example, I'm aware of areas in which organised youths check all the car doors in a neighbourhood - hoping someone has forgotten to lock and alarm their car. Under these circumstances an alarm system does no good... It is important to discriminate... Burglar alarms also offer no protection from vandals - whereas a CCTV with night vision may well do - if only by identifying weaknesses in manned security. I imagine an infra-red video surveillance system would be an extremely good way to improve security for applications such as monitoring business car parks; monitoring entranceways to identify where layabouts trespass before any real harm occurs - as well as providing some way to counter graffiti tagging and other illegal unpleasantness.

I've long thought this would be a fun project - but as yet I've not found time to tinker.

Re:Burgler Cam??

[ebob]

Not so stupid.

A couple of months ago a guy in rural San Diego did exactly that and nabbed some identity thieves stealing folk's mail from their mailboxes at night. Here's the story from the San Diego Union Tribune:

http://pqasb.pqarchiver.com/sandiego/

Re:Burgler Cam??

[deacon]

Sure. But if you want to step up in image quality and view range:

Use this camera, illuminate with this device and use a C-mount lens from this page if you are comfortable with removing the electronic iris in some of these older, but superb qulity, lenses.

You will be able to read a license plate at 75 feet in complete darkness.

6.9Mb DivX AVI file

[Anonymous Coward]

Sorry, man. Slashdotting in progress.

IR filter

[RikRat]

Hmm, I opened my sweex webcam (the same he has) and unscrewed the lens. But my IR filter is round (so not a square as in his webcam) and won't come out.

Re: IrDA != infrared webcam

[Alwin Henseler]

I do wonder what the most common applications for Linux/IrDA are, considering the trend I've observed where among the most commonly requested Linux HOWTOs recently have been 'laptop', 'infrared' and 'webcam'. Is everyone building infrared webcams?

Maybe you're confused here, and should check out some of those HOWTO's yourself (and read the article for once), to see what it is all about?

To use a webcam for looking in the infrared spectrum, is not the same as using infrared light for shortrange communications (IrDA, TV remote etc).

Not all cheap webcams have filters.

[OneDeeTenTee]

If you're lucky the webcam won't have an IR blocking filter.

You may want to check it with a remote (or just put your IR passing filter in front of it) before you take it apart.

Re:Not all cheap webcams have filters.

[bcmm]

I have a camcorder (analog, large by modern standards) which has a mode in which it takes infrared images. It has a bright infrared LED on the front, so it can work as an active infrared system in total darkness (it gives weird green-and-white images). The thing is, when it is in normal daylight mode it can still see IR, and you can see, as you say, remote controls as flashing lights. Which makes it's own remote control look silly when we use it to start/stop recording.

Re:Not all cheap webcams have filters.

[Zinob]

In fact it does at least mine, but its quite crappy (besides IR is a bitch to block perfectly, haven't seen a single filter that is able to kill to 100% of it, so you will see a remote even though your camera has one). On my QuickCam express it is located behind the rearmost lens i.e. the one located closest to the sensor (which it glued to the housing) so you have to (carefully) pry that one loose (i used a really small screwdriver and an awl), then remove the little clear square of glass behind it (looking just as in the pictures(!)), and wollá! You have even better reception of IR (err considering the quality of the CMOS sensor i guess i should say "less bad").

Many high-end web-cams have day/night and pan/tilt

[Anonymous Coward]

We've been buying VB-C50iR cameras from NuSpectra for construction monitoring. We can do all this--perhaps not as cheaply!

Pan/tilt/zoom control, day night filter (changes to IR/Night mode on a schedule)... Plus 26x optical zoom rocks.

NuSpectra has a demo camera out of their office in San Francisco.. See demo in upper right corner of page.

We also use the SiteProxy software that lets us build time-lapse movies from all the camera's preset positions on the fly.

Check em out!

Re:WEcam HOWTO?

[InfiniteWisdom]

I've heard of a webcam, but never a wecam.
Hence the HOWTO, duh!

OK.....

[mr_z_beeblebrox]

So the article details a cool hack, props. What I want to know is.....why was I able to download the 6.9 MB AVI file at the end. Isn't his server supposed to die or something? I can never download the files referenced by a /. link. Is something wrong?

Re:Infrared Technology and the Chinese Threat

[nounderscores]

Lets hack some cams, stick them on $89 lcd handheld tvs and send them to tibet as freedom fighter nightvision goggles.

It might make the fight more interesting.

this is true of almost all modern cameras..

[Mark19960]

altho, most that ive seen ahve the IR filter directly attached to the CCD.
you would remove the CCD, then remove the 'piece of glass' from it.

some cameras achieve this effect differently, I have not quite worked out how they work.
For example, Sony camcorders that have 'nightshot'
also have an IR filter, but I suspect its something different. the switch not only engages some IR illuminators, but does something in the lens block itself. (switches something in/out mechanically)
I know that the IR filter at the CCD remains there, its in a fixed position.

I am now curious and have to dissasemble a sony lens block to see :)

I used to work on cameras, and I have removed the IR filters on cameras before for a bit of fun.

if you can get enough IR leds going you can get it pretty well lit.
Altho, the resolution is probably not going to be that great at a distance.

X-Ray Specs

[lildogie]

Wow, just like those funny glasses I bought from the ad in the comic book back in the 60's.

Re: makezine, ob. They Live reference

[rubycodez]

U.S. notes not too interesting, just big black letters on light background saying "THIS IS YOUR GOD"

Re:Infrared Technology and the Chinese Threat

[budgenator]

Actualy this is pretty much WW-II style technology, the old Sniper-Scopes used active IR like this web-cam mod. Now the problem is passive IR is so common firing up an IR illuminator is like painting a bull's-eye on your forehead. It's so common, we put blue filter on our flashlights to block the near-IR and IR output; visible light is less damgerous the IR at night!

The day is still young...

[Shazow]

Everyone is still asleep from their late-saturday-night D&D sessions.

Give it time... :-)

One question

[gone.fishing]

Will this mod void the warranty?

(it's funny, laugh)

Heat Seeker

[Doc Ruby]

We need a demo of pix of his hot neighbor in her nightgown. Too a HW hacker never sees her that way around sunrise.

Look for heat loss?

[crow]

Will this capture the right range of infra red to detect heat? If so, then I could see using it with a laptop on a cold day to see where I need to improve the insulation on my house.

Re:Look for heat loss?

[SmurfButcher Bob]

Nah, you don't need to spend that much. You can bottom-feed off the low end for about $13 grand for a fixed-notch greyscale bolometer type. Better ones will run up to 20 grand, and offer a full floating, variable width notch with false color representation.

Granted, these are all intended for structural firefighting, so they aren't cheap. But they *are* intended to be dropped, kicked, and roasted. Obviously, you'll trade weight for battery life and heat shielding - the Draegers have full Ni cladding and can survive long exposure, but they weigh a lot. The Scotts are much lighter, but don't get them above 600 degrees...

trashed my kensington videocam

[emptybody]

I unscrewed the lense end - the same way you fine tune the focus.

it then proceeded to fall over due to the usb cable coming free in back.

I now have a little stack of lenses that I need to figure out the proper way to orient.

2 lenses - 2 ways = 8 combinations.
a third lense further out = x2 more combinations.
a fourth lense on the outsite = x2 more combinations.

Total 32 possible ways to re-assemble this little bugger!! DAMN-YOU!!!!

Worst of it is, the pink lense is a lense and not a flat glass filter. I cant use this cam :(

Anyone have a blow-up of this cam -
Kensington VideoCAM VGA PC Camera
Model#67015

Disgruntled ISP customer?

[The-Bus]

This guy must just be mad at his ISP or whoever does his hosting.

The ~7MB video file at the end of the page doesn't even have anything to do with IR video. It's like he wants us to take the server down.

So do him a favor and just download it 8 times.

Re:The effects of IR on follicles

[Fishead]

What's really cool is looking at a person through a 3-5 Micro-Meter (aka "Far IR" thermal camera (think military and very expensive). Your hair looks black near the ends, and red near your scalp. Glasses appear black, veins are sometimes visible, and you can see 2 guys in a zodiac up to 20 miles away (which is why the military likes them so much).

This webcam mod is pretty cool, but only for us normal folk without $40,000 to spend on a REAL thermal camera.

If you want a time-lapse capture app for free...

[maird]

...Get one here: http://www.mair-family.org/Downloads/ Geoff says the software he had isn't very good. I couldn't find anything I was prepared to pay for so I wrote my own and publish it at that link. Sorry Windows only and WMV output. You can read the feature list for yourself but, in terms of Geoff's difficulty, it will capture frames at between 4s and one hour per-frame (configurable) and create a 15fps WMV.

Go ahead, /. my web server...Hopefully my ISP is tolerant.

Re:Many high-end web-cams have day/night and pan/t

[Fishead]

I usually prefer to use a high intensity Xenon light with a filter on the front. Xenon has a nice spike in intensity at about 700nM and makes an awesome covert searchlight.

See through clothes!

[SiliconEntity]

We all know the real point of this - to let you see through clothes like the infrared video cameras that came out a few years ago.

Re:See through clothes!

[shish]

He has a picture of himself in a multicolour top; it shows up as a solid colour, but not see-through :(

Re:The fun of spelling!

[Tore S B]

It's "It's" not "Its"! :)

See through camera

[MaxBlue]

Didn't Sony have an issue a few years back with their digital camera's seeing through bathing suits? Wasn't it have something to do with IR?

Was their fix to add IR filters?

alternative approach

[tverbeek]

Or just accelerate your webcam enough (toward the object you wish to photograph) to blue-shift the infra-red into the visible frequencies. Put it on a really-high-speed ferris wheel or merry-go-round and synchronise the snapshots to its rotation if you want to keep it "stationary". Compensating for the doppler shift in the signal from the camera is left as an exercise for the reader. But no disassembly or modification of the camera needed!

Warning: state of USB webcams on linux

[jago25_98]

I bought a sweex webcam like the one in the guide.

Indeed the usb chipset is supported (sn9c103), but the sensor isn't. So I'm sending it off to Italy for Luca the developer, well it's no use to me.

USB webcams can have different sensors within the exact same model, so you never really know when buying one whether it will work for sure.

Hopefully this will change if the USB video standard (similar to firewire video standard), comes about.

In the mean-time think about firewire cameras.

tried it(using just swiss) but whitout the film

[esoinila]

Hardest part was putting the Logitech QuickCam back together the right way -- because which ever way which part was was quickly forgotten in the process. I didn't have any film handy but the cam now shows security marks on 50 Euro bill quite nicely. The picture is more of black and whitish without the filter. It sees through things.

Now just good lighting. I have a bicycle led-light with individual lences for each led. One of these with proper leds might work nicely as home surveillance system.

But sure was and is fun....much thanks to the author.

This is great

[eanmeyer]

Five minutes after I read this I dug out my old IBM PC webcam and started tearing it apart. Five minutes later I had a working IR webcam. Now I want an IR flashlight.

Tomorrow on Slashdot...

[servoled]

Tomorrow on Slashdot, how to turn an ordinary car into a convertible by removing the roof.

Re:Hack to bits your remote...

[kid-noodle]

Somewhat to my amazement, this actually worked quite well despite my dramatic ineptness with electronics.

Pictures are in this thread.

I'd post a pic of the setup.. But I'm ashamed of it. Sellotaping wires to a battery just isn't .. y'know.. valid somehow.

Did it to my 300D (Digital Rebel)

[purduephotog]

Took the whole camera apart, removed the optical pass filter from the CMOS chip, replaced it with an IR-PASS filter (rejects lessthan 750nm)... and I have a visible focus / IR sensitive camera.

Great shots, too

1st test shot here: http://www.deviantart.com/deviation/12473546/