FreeTrack Forum

Hello fellow freetrack users
I've recently been able to convert my labtec webcam pro to a IR cam, and it works just great with freetrack.


WARNING: This conversion is IRREVERSIBLE, and can damage your camera if not done carefully enough, so think twice before you start, and work slowly and carefully if you do.

So getting to the point, here's some info on how to do it:
First, you'll need to unscrew the lens from the camera. Before the end they will start turning harder - there are latches preventing the lens from falling out, but since that's just what we're trying to accomplish, just ignore it and keep turning until you have the lens in you hand. Put the camera aside, since there's nothing we need to do with it. Covering the opening where the lens were with something might be a good idea, since any dust gathered on the sensor will reduce image quality.
You'll notice that there's a plastic ring holding lens together inside the tube, as seen on this picture:
Pic1
You should have no trouble prying it out with a sharp knife, like this:
Pic2 (of course you should hold the lens with the other hand, but i had do take the photo somehow )
After removing the plastic ring, you'll be able to get one of the lens out, just watch out not to scratch it:
Pic3
Bellow it is another plastic ring, this one much thinner. Be careful not to lose it.
Here's how it looks disassembled:
Pic4
See the orange reflective coat on the flat side of the lens you took out? That's the IR filter. The problem is that it is a coating in the lens, not a separate part. It has to be removed mechanically, and obviously, cannot be put back. Fortunately, the lens are made of glass, so they can survive the procedure without harm. I used a Dremel  rotary tool like this with felt polishing attachment (picture) and some polishing compound. This way the lens didn't have any scratches on them after removing the IR filter. But as i said, they're made of glass so if you don't have access to polishing tools, you could try using very fine sandpaper or a sharp knife and polish the lens afterwards (warning - do this at your own responsibility).
After the hardest part - removing the filter is done, you can insert the visible light filter into the camera to make it see only IR light, or just leave it as it is to make it work in both daylight and IR light. Freetrack works best if the ambient daylight is filtered out, but you can always attach the filter outside the lens so it can be removed at will.
I decided to mount the filter inside the camera, so i cut out three small wheels (about 8mm diameter - the size of the thinner plastic spacer from inside of the lens) from black of part developed of photographic film:
Pic5
[EDIT]The filter can also be made of magnetic disk of a 3,5 inch floppy. The problem with this solution is that it does a bit too well - with it you will no longer be able to see the reflected IR light, and therefore won't be able to take IR pictures. However It will make the freetrack threshold setup much easier, since you probably won't be able to see anything but the LEDs - see my post below for comparison[/EDIT]
Just one last step before you finish - clean the lens thoroughly, best using some pure alcohol like isopropanol, or ethanol, or at least using some detergent. Any fingerprints remaining on them will reduce picture quality. Also chech if there isn't any dirt or dust inside the tube on the next lens before putting the ones you removed back.
Now it's time to put it all back together - the thin plastic spacer ring goes in first, optionally is followed by two or three layers of the visible light filter, then the lens - flat side goes down towards the filter, and finally close the lens by pushing back the thick plastic ring that held it all together.
Just screw the lens back, adjust focus, and congratulations - you have an IR cam
Here are some pictures taken with my modified webcam:
A Polish 10zl bill - in normal light the print is visible on the whole bill.
My freetrack cap at minimal exposure and minimal gain setting - I think I'll have to reduce the current to the LEDs - they're a bit too bright now

Good luck

And by the way, I'd like to thank freetrack developers for all the hard work they put into this fantastic project

What a nice contribution !

Many thanks !

Rémy

http://www.bsk.vectranet.pl/~lachrafal/misc_images/LabtecIR/Picture1.jpg
http://www.bsk.vectranet.pl/~lachrafal/misc_images/LabtecIR/step5.jpg

The image is not sharp because you use 3 layer of film. Use one magnetic disk from a floppy it's work much better in my case.

EFG_beber - Yes, you're right - i tried it too, but if filtered out some of the IR light as well, and while it worked perfect with freetrack and IR LEDs since it was able to pick only strong sources of IR light, i still wanted the cam to be able to see the lower intensity reflected IR light just to play around with it. Oh, and the these LEDs are VERY bright - they get about 90mA, so most of the distortion you see is a lens flare - i also had to put the brightness down and contrast up, so the image is very low quality.
Here's a bit more sane setting - about 20mA for the LEDs, and they are shining straight at the cam, just like in previous case:
Photo film filter picture
And here's the same cap with the same power source, but with magnetic disk filter:
Magnetic disk filter picture
Of course it's up to whoever modifies the cam if he/she wants to be able to use the camera only with FT (then magnetic disk filter is the best), or also as a IR/nightvision camera (then the photo film still works the best).

I've been thinking of making easily interchangeable filters for various appliances - then without any filter it can work as an ordinary color webcam, but with much better picture quality in low light/artificial light conditions than unmodified one, with a photo film filter it can be used to watch the world in IR, and with a filter made of floppy disk it rocks in freetrack

When i come up with something worth showing, i'll update the first post.

Ok, I understand. Happy it's work fine.

This guide is now incorporated into the website and no longer needs to be stickied.

See Webcam filter removal