Print
In order for our setup to work, we needed a camera that senses infrared light, but not visible light. It sounds expensive, but you’d be surprised. In this section, we’ll show you how we created an IR camera with excellent resolution and frame-rate for only $35—the price of one PlayStation 3 Eye camera. “But that’s not an IR camera,” you say? We’ll show you how to fix that.
As it turns out, most cameras are able to sense infrared light. If you want to see first-hand proof that this is the case, try this simple experiment: First, find a cheap digital camera. Most cell phone cameras are perfect for this. Next, point it at the front of your TV’s remote control. Then, while watching the camera’s display, press the buttons on the remote. You’ll see a bluish-white light that is invisible to the naked eye. That’s the infrared light used by the remote to control the TV.
However, for the sake of preserving an accurate color balance, most cameras have an IR filter applied, which causes the camera to detect only visible light. It’s possible (and in the PS3 Eye’s case, reasonably easy) to open up a camera, remove the IR filter, and replace it with a visible light filter, making an infrared-only camera.
But before we could get at the PS3 Eye’s sweet, sweet IR filter, we had to crack it out of its shell. To do this, we started by flipping it over and popping off the four little black disks glued over the screw wells. We had seen this done using an X-Acto knife in this excellent video, but when we tried to recreate the feat ourselves we didn’t manage to do anything except snap the tip off our X-Acto's blade. Instead, we found that using the corner of a regular rectangular razor blade to pry the disks off was more effective.
Once the covers are gone, the screws can be removed and the two halves of the shell pulled apart. This is a little easier said than done, though; the shell is glued together. To break it apart, we had to use a process that involved going around the seam that joins the two halves of the camera, inserting a flathead screwdriver and twisting every centimeter or so, until the halves separated.
With the back half of the shell removed, the circuit board is exposed. First, we removed the two screws at the bottom, labeled (a), allowing us to removed the camera’s base, then we unscrewed the five screws labeled (b) and separated the circuit board from the front casing. Finally, we removed the two smaller screws that had been hidden behind the camera's base, freeing the lens from the board and making sure not to damage the sensor beneath it.
The infrared sensor is the innermost piece of glass on the lens assembly. When it catches the light, it looks ruby red – a dead giveaway that this is the piece filtering out infrared light. In order to remove it we simply used a razor blade to gouge out the plastic in a circle around the filter, allowing us to easily pop it out.
So now the IR filter is gone, but we need a visible light filter to replace it with. You can buy fancy IR bandpass filters off the internet, which will give the best results, but it’s also possible to make a very passable (no pun intended) filter out of the magnetic tape inside of a floppy disk, or a couple of pieces of exposed film negatives. We went with the magnetic tape method, and (after a few false starts) were able to cut a square that fit nicely into the square space between the lens assembly and the image sensor. We reassembled the PS3 eye, now converted into an IR-only camera.
The PS3 Eye camera has two focus settings, for a wide or narrow field of view, which can be selected by twisting the plastic ring around the lense. It’s worth noting that the removal of the IR filter messes up the focus of the PS3 Eye slightly, and we found out through trial and error that in order to get it to focus sharply, we had to twist the focus ring very slightly, so that it was “balanced” between the two settings that it normally snaps to.
Comments are closed on this article
lbclofy
April 09, 2009 at 9:17pm
would you be able to use a rear projection screen tv instead of a projector?
Devansh
April 09, 2009 at 8:59pm
Hey ppl. i must thank Maximum PC for their efforts on this remarkable machine. I am planning to make it as my Final year project at School. Can you guys tell me where you got the applications you have shown in the video as well as the bonus section?? thanks a ton. and once again, a great job!!
MAJORzer0
April 16, 2009 at 1:43am
The links are included into the article.
This is a great bit of fun. I wish I had the time to tinker with it.
~No one said it would be easy....they just said it was worth it...~
linkmaster6
April 09, 2009 at 10:50am
Love the idea of this project and so do the guys I work with but I've noticed a couple things that are missing that would be nice to see.
First would be how the LEDs are connected to the acrylic. Looking at the steps I see the LEDs being soldered together from in hole in a board but a in later shots of the acrylic it looks like they are embedded or stuck to it.
Second would be the position of the camera. Call me stupid but is it suppose to be set like the leds? underneath looking up at the acrylic?
Third would how the projector is mounted, where the mirror is set. Is it hung dead center looking down at the mirror? A model of the projector would be nice, that way others would know what to look for.
Fourth. More specs on the computer used would be nice, such as OS, videocard used, PSU Wattage
Well thats the end of my rant. My boss has been looking to do something likes this for our store.
robtom
April 09, 2009 at 8:51am
no that is using it as something else it doesn't link to your computer as a camera it becomes an HID which is Human Interface Device. I did that project too.
nsk chaos
April 08, 2009 at 6:45pm
i think i had an orgasm when i first read this lol =) its good to know that DIY touch screen is within my budget hahahaha.
great article ++rep to MPC
winmaster
April 08, 2009 at 3:52pm
You guys went through a lot of trouble to build a touch screen when you could have just used the camera on a Wii Remote and an IR light source. You don't even have to actually buy a Wii, you can just connect the Wii Remote to the PC using Bluetooth. More info here:http://www.youtube.com/watch?v=5s5EvhHy7eQ.
--------------------------------------------------------------------------------------------------
The quick brown fox jumps over the lazy dog.
ccshou
April 08, 2009 at 12:30pm
I think I would need one whole year to build one for myself lol.
Hope to see it on market with reasonable price soon.
sparky81795
January 30, 2010 at 9:46pm
if the ps3 eye can see IR without removing the filter why do i need to remove it? does it see a broader spectrum after removal? i'm just not sure i want to perminantly modify my toy since i have a ps3 and have occationally used it from time to time. thanks for the help
robtom
April 08, 2009 at 7:26am
Actually with FTIR it works quite well. There is also a way to do it without using custom IR LED strands. IR lasers are possible one of the neatest ways to do it. My friend made one and with it you don't really have to worry as much about the room being dark and having no lights on. The lasers are so bright that they pretty much block the effects of ambient lighting.
Paulfo
April 08, 2009 at 7:49am
That's cool. Do you have a link to the laser parts used?
Thks!
Paul
wotudo.net
Paulfo
April 08, 2009 at 7:07am
I recently showed my mutli-touch machine at Maker Faire UK.
Rather than using FTIR I used the rear IR diffused method. This required no custom electronics because I used the CCTV IR illuminators as my IR source. I then modified an Xbox Live Camera to have a IR Band filter and then it was just the table I had to build. I did the whole thing for less then £90 (so about $140) because I had the Xbox camera (but almost any web cam will do) and I borrowed a projector from work!
I made a video of it, you can see how I put it all together at http://www.youtube.com/watch?v=izwb_uCitxU
I also used an multitouch application built by members of the NUIGroup with XNA. This gives a great user experience - very Surface like :-)
Its all in the video so please take a look! My blog has more details - I'd be happy to help others looking at doing this sort of thing so ping me if you need help!
Paul
wotudo.net
Paulfo
April 08, 2009 at 9:05am
in response to some questions I've quickly posted some more detail on my blog regarding my illumination set up:
http://wotudo.net/blogs/wotudo/archive/2009/04/08/multitouch-illumination-details.aspx
A walk through of the application I used is also on YouTube. The app was written by some cool NUIGroup members in Spain
http://www.youtube.com/watch?v=TQIQwg_6XWI&feature=channel_page
Cheers
Paul
wotudo.net
ptatlow
April 07, 2009 at 9:13pm
The concept and video are MOST amazing! I've read the "how to" several times now, and there appear to be some rather large holes in the concept.. ie: Exactly WHICH type of LEDs did you buy? I went to the website you mentioned, and there are many,many options to choose from. Where do you position the camera? How did you mount it? Where is the projector placed? How did you mount it, etc? Are the rest of the juicy secrets and more details contained in your magazine that are not placed out in the open for the general public? I'm considering subscribing to your publication, however this has left more questions than answers.
Look forward to whatever additional details you are willing to provide.
Phillip
robtom
April 07, 2009 at 6:39pm
I am a highschool student. I have made one of these and in regards to
the screen maximumpc used the team of two other students I worked with
to make this we found the best screen design that works the best is
when you actually don't use silicon and that vellum which we found that when it sees as much use as ours did that it would cause the silicon to bubble and actually cause more problems than it was worth. We took another layer of acrylic that was much thiner, I can't remember the thickness off hand, and sandwhiched it inbetween the two pieces of acrylic, the thicker one on top with the LED's. This worked much much better and doesn't cost too much more. Granted you would have to possibly clean the arcylic on top occasionally but it works extremely well.
matroska
September 16, 2009 at 8:38am
Greetings to all))) People, huge requests... Who can help with this question I will is grateful.
Please, who did this project?? Help me!!!
There is any circuit of assemblage of this device? How all to connect?? Many gathered, please help!!!!
Who agrees to me to help, write, here e-mail Vera.krylova@mail.ru
In advance thanks (In advance I apologise - English language I know not so well)
Geminus
April 07, 2009 at 6:03pm
As I look over my 2 year old used keyboard, I notice that certain keys seem 'polished' due to my micro-sanding fingertips. My question is this, "Could there be any impact to usage or image clarity due to this micro-sanding?"
I work in an industry that is spearheading the Microsoft (sic) Touch for cruiseliners. So, my query pertains to how wear and tear 'chemicals, dirty hands, drink glasses, etc... might affect the usability of these devices in the long term?'
Polycarbonate surfaces wear easily as compared to glass ones. Would a sandblasted glass surface weather better or last longer?
-Will
SparkyTCFH
April 07, 2009 at 1:21pm
Instead of vellum, you should use a thin sheet of matte-finish clear Lexan polycarbonate. It would wear a lot better than the vellum.
You can usually get Lexan sheeting at sign supply or specialty plastics places.
schinkinatror
April 07, 2009 at 10:24am
So would there be a way to play supreme commander or company of heroes with this?
Ananth T Sarathy
April 07, 2009 at 9:13am
I know that the Surface uses 5 cameras. What is the benefit of that? Can multiple camera's be supported in this build?
cerupcat
April 07, 2009 at 1:51pm
The 5 cameras are to increase resolution and allow for a shorter table.
Multiple cameras will eventually be supported in the software. It's a work in progress. Stay tuned to the nuigroup website to see updates in both hardware and software.
Ananth T Sarathy
April 08, 2009 at 11:05am
Each Camera taking an area of the display, thus allowing for more resolution, shorter distance to view their respective area.
Wilt the NUIGroup software end up being a driver/device that word work with Windows 7? IE would be considered a touch device therefore enabling it's native touch support? This is all very fascinating to me. I can't wait to get my work bench set up when I move!
s3kShUn7
July 22, 2009 at 11:01am
Multi-Touch vista now has support for windows 7. Meaning, it thinks you own a real touchscreen, like the hptouchsmart.
howman
April 07, 2009 at 7:50am
another trick is to use a palm sander with 120 grit then 220 grit and finnaly 400grit paper on the edges, then use a propane torch to flame polish the edges. Just go over them a few times with the torch and you will have a glass clear edge. Practice on a scrap peice first as it takes a bit of getting used to. The edge is way clearer than using a dremmel and you won't burn out your ear drums or end up with specks of black polish compound all over your face. Remember to keep the torch moving or you will burn the acrylic, and pull back the protective coating off the faces of the sheet a couple of inches so you don't burn it.
bland
April 07, 2009 at 6:43am
Very good writup.
Just couple questions. How durable is the Vellum material. Would it work in a school environment, or would it get destroyed? Also I notice in the video you can see it moving around as you drag your fingers on the screen. Would it be possible to use a lite glue layer after the silicone to make it stick to the acrylic to stay in place, but still have the same affect since the silicone layer would still be there?
dan171
April 07, 2009 at 3:49am
this project is just awesome, im on ebay right now lookin for a 2nd projector to go in this!
would be great if you can upload some pics of inside the cabinet to show where the camera, projector, mirror and pc is!
cerupcat
April 06, 2009 at 10:22pm
Awesome work guys! I'm glad nuigroup was able to help you reach your goals! :)
I notcied an error in the article that states nuigroup is 'New' User Interface Group, but it's 'Natural' User Interface Group. If you can correct that, i'd be great for the community :)
Keep up the great work, and I hope to see more from you in the future! Feel free to refer any specific questions to our community forums on nuigroup as you see fit.
Thanks!
-cerupcat
atcastle
April 06, 2009 at 11:41pm
Good catch, and I'm glad you liked the article! I fixed that mistake.
cerupcat
April 07, 2009 at 1:52pm
Thanks Alex, we appreciate it.
Keep up the great work! We'll continue to be supporting ya! :)
matroska
September 16, 2009 at 8:34am
Greetings to all))) People, huge requests... Who can help with this question I will is grateful.
Please, who did this project?? Help me!!!
There is any circuit of assemblage of this device? How all to connect?? Many gathered, please help!!!!
Who agrees to me to help, write, here e-mail Vera.krylova@mail.ru
In advance thanks (In advance I apologise - English language I know not so well)
Keith E. Whisman
April 06, 2009 at 9:54pm
Oh yeah I noticed in the video that you guys were playing a video and it appeared to be Leaked Work Print for XMen Origins Wolverine.
Are my eyes lying to me or was that just a preview of the movie on the website?
willsmith
April 06, 2009 at 10:09pm
It's just the trailer. You can download it at Apple's site or any number of other places, perfectly legally.
We don't advocate piracy at Maximum PC.
Keith E. Whisman
April 06, 2009 at 9:03pm
I would love to build one of these for myself and one for my children. This is freaking awesome. I liked the video. You guys are definately ready for Video podcasts. The quality of the video was excellent. I hope this video makes it onto the maximumCD.
Great article.
vistageek
April 06, 2009 at 8:40pm
I built one of these about a year ago into my multitouch table and then did a clone display to the projector. So, I can control media center with my multitouch coffee table. (Nerdgasm) By the way, touchlib comes with a windows mouse driver so the multitouch can be used in windows and other programs.
jwalch.hawk
April 06, 2009 at 8:30pm
So this is the mysterious 'how to' referred to in the podcast, yes, Alex?
AWESOME story. Color me impressed.
KLM2010
April 06, 2009 at 7:37pm
Nice. Can you use the screen to show the OS as well, and will it play nice with the multitouch applications? And is there any way to control the OS using the screen? The screen would obviously not replace the keyboard but it would be cool if you could use it like a tablet instead of having to use a mouse.
Also, how dark does the room have to be in order to see the display?
This is a great article. if I can find a projector, I will build one of these this summer...
Siberous
December 16, 2010 at 9:22pm
I have see alot of these touch screen and most of them are all flat, either on the wall or on a desk, but then i saw one on BuildItBlog, a newer website with some pretty cool builds, and Its a Curved Desk, It uses 2 projectors i think but the finaly product is Awe inspiring! Wish it could be a little smaller but still Fantastic!
http://builditblog.com/2010/12/bend-desk/
Stockislander
April 06, 2009 at 7:27pm
Great project, thanks! I noticed a huge delay on the keyboard demo... wouldn't work for making music. No asio drivers?
big_montana
April 06, 2009 at 5:32pm
I would like to know what your total cost of the build is. You say it is inexpensive to build, but give us a number.
atcastle
April 06, 2009 at 5:56pm
I didn't put a total cost because how much you would pay for the materials used in the build can vary a lot based on where you live. Here in San Francisco, with a good local source for acryllic and vellum, we paid somewhere in the neighborhood of $350 for all the supplies. That includes the LEDS, wood, vellum, camera, mirror, heat absorbing glass, and silicon. If you don't already have a projector to use, that'll cost extra, although sites like craiglist and ebay have some pretty good deals on used projectors.
It's not pocket change, of course, but it's definitely a whole lot cheaper than any of the commercial multi-touch solutions available right now.
Siberous
December 16, 2010 at 9:24pm
I have see alot of these touch screen and most of them are all flat, either on the wall or on a desk, but then i saw one on BuildItBlog, a newer website with some pretty cool builds, and Its a Curved Desk, It uses 2 projectors i think but the finaly product is Awe inspiring! Wish it could be a little smaller but still Fantastic!
http://builditblog.com/2010/12/bend-desk/
TheMurph
April 06, 2009 at 4:38pm
Tres cool. I'd totally build one if my cat wouldn't have a field day all over it.
Justin.Kerr
April 06, 2009 at 5:50pm
It does seem that cats are inexplexibly drawn to expensive gadgets.
Strange creatures they are...
Havok
April 06, 2009 at 4:37pm
I almost lost my supper reading this artice, my jaw dropped so much! This is astoundingly cool! I might build one with my dad for a neat media based PC.
Imagine, firing up your torrents and pirated videos/games, all for cheaper than those touch based systems, but with a bigger screen!
;)
Thats my shout out to those who are too cheap to buy movies and games, y'know, help out the failing economy?
OMGWTFBBQ
