Life at the Limits: Earth, Mars, and Beyond

an educator workshop and fieldtrip

Infrared-Enabled Webcam

A Technology ‘Hack'

By Allan Treiman

Purpose. To view infrared light in a rainbow spectrum, you must modify a webcam, a cheap, computer-mounted CCD camera. This page gives general instructions and web links.

Introduction. The light sensors used in digital cameras are either CCDs (charge-coupled detectors) or CMOS detectors — the latter is more sensitive and appears in newer, fancier, and pricier webcams. Both types are more sensitive to infrared light near the visible spectrum than they are to visible light (see graph). So, for a CCD/CMOS camera to match what a human sees, all of the infrared light (wavelengths longer than 700 nanometers) must be cut out with a filter. By removing this IR-cutout filter, ‘hacking the webcam,' you can restore the its response to infrared light.

 
Light detection efficiency of a CCD sensor versus the three types of cone cells in the human eye.

Equipment needed:

  • A color webcam that you are willing to play with (or kill)
  • Small screwdriver
  • Small knife
  • Ingenuity, and some skill in small parts

  Light detection efficiency of a CCD sensor versus the three types of cone cells in the human eye. CCD detectors are more efficient than cones, and are sensitive to infrared (invisible) light with wavelengths out to ~1000 nanometers (nm).

Procedure. This is pretty general, because there are about a million types of webcams out there, and new ones are being sold all the time. I am working on fairly detailed instructions on a couple common types of web-cams, sometime soon now.

1. Try to remove the lens by unscrewing it all the way out (counterclockwise). If this works, you're golden and skip to step 3. Otherwise, the lens assembly is being stopped by the webcam case, and you will have to disassemble the case. Go to step 2.

2. Open up the case of the webcam, and extract the lens assembly. This will vary depending on what sort you have. Look for little screws, or for prongs that hold the parts together. Do not lose any parts, and make rough drawings so you remember how all the parts fit. These web sites have more specific instructions, depending on the sort of webcam you have.

Ball Webcam
Three-legged Cyclops

Two-legged Webcam
If you have a ball webcam,
try this site.
If you have a three-legged Cyclops,
try this site.
If you have a two-legged leaner,
try this dissection.
     

 

3. Once you have extracted the lens assembly, look for the IR-blocking filter. It will be greenish/bluish glass and/or a surface that reflects pink or red. Most commonly, the IR-block filter sits between the lens assembly and the CCD / CMOS light detector (the flat black shiny plate on the green circuit board).

 

(a) The IR-blocking filter is a piece of glass, bluish or reflecting reddish, attached to the inside of the lens assembly. Some are square, some are round. Some are glued on, others are held by a gasket or a retaining sheath. In any case, remove the filter!! Image A
(b) The IR-blocking filter is a plastic coating, reflecting reddish, on the lens surface closest to the light detector CCD or CMOS. This is how the webcam at our workshop was. Take a sharp, small penknife, and scrape the coating off. Test first at the very edge of the lens.
Image B

(c) The IR-blocking filter is a bluish glass plate, reflecting reddish, inside the threaded lens mount. Unscrew the lens mount from the printed circuit board, and pop the filter out.

(d) The IR-blocking filter could be hiding inside the lens assembly, between its individual lens elements.

(e) The lens assembly is a single unit of plastic, all molded together. The cheapest way to manufacture, but the worst for us. Quit.

Image C

(f) The IR-block filter is glued onto the surface of the CCD or CMOS light detector. This is common in digital cameras, but uncommon in webcams. Removing filters like this can kill the webcam, and perhaps the better plan is to put it back together and try another webcam. If you decide to proceed, open up the webcam body if necessary, and use a sharp small knife to CAREFULLY cut around the filter.

 

Image E

4. Remove the IR-blocking filter. Pry it out, scrape it off, whatever.
5. Re-assemble!!! View the world with infrared light!!

Extension. Some users, especially the astronomers, want to view the world only in infrared light. Several of the websites show how to replace the IR-block filter with Visible-block filters. The simplest such filter is a couple layers of color photographic film negative, the part that is totally black.

Webcam Models and Their IR-Cutoff Filters:

From [1] How to make a webcam work in infra red unless otherwise noted.

As models and manufacturers change rapidly, this list is surely out of date, and your webcam will have to be treated as an individual! Also, don't be surprised if the webcam is not like claimed here. Commonly, manufacturers sell slightly different models (that work the same) under the same part number. And, most of these models are not being sold any more.

I. Cameras with glass plate filters outside the lenses. [1]
Aptek Hypercam Mobile
Ariston Ball-shaped camera
Creative – older model webcam
Dexxa Webcam
ICatch (VI)
Logitech Quickcam Zoom
LogiTech QuickCam Pro 3000
Logitech older models
Philips PCVC740k and 840k
Philips older USB model (not the sound one)
SiPix Stylecam Deluxe
Sony Eyetoy
Vgear2 Minicam
Vivicam 3340
Vmicro 301x
Unknown type

II. Cameras with Lens coating filters
Alaris weeCam (NOT recommended – parallel port output)
Creative NX Pro
Intel CS
LabTec "Webcam USB PC Camera"
Oregon Scientific Flashcam
Sabrent SBT-WCSS & WCCK
(Xirlink) IBM PC Webcam (The filter is hard to find, so one geek says)
ZoomCam (ball-shaped)

III. Cameras with filters inside the lens assembly (between lenses) – difficult.
Logitech QuickCam Express
Unknown

IV. Cameras known not to work or difficult
Labtec Webcam Pro. Lens is a molded unit. Not possible to remove IR filter
Logitech QuickCam Messenger
Creative PC-CAM 600

References:

[1] How to make a webcam work in infra red
Description of how to remove the filter on older-style web-cams, the ones with the square bit of glass. Includes other nice features:
a list of cameras that can be modified this way, and some that can't;
instructions to filter out visible light, so the webcam sees only in IR, and
images of all sorts of stuff (money, coke bottle, etc.) in IR.

[2] How to Make a Webcam Into an Infrared Camera
Concise instructions for the simplest case of a glass plate filter attached to the back of the screw-out lens.

[3] Infrared-sensitive modification for Color QuickCam camera
Blow-by blow instructions for opening up a ball webcam (Color QuickCam or similar) wnere the lens assembly doesn't just screw out of the camera.

LIVEJOURNAL
A journal page of ideas and solutions for modifying webcams. Lots of specifics about individual web cams, and another list of which ones work and which don't.

HACK A DAY
A discussion of web camera hacks.

GRYNX
Detailed photos on modifying a Philips PCVC740k or PCVC840k. It has a round glass filter.

Mod Your WebCam - Infrared
Brief instructions on how to remove an IR filter that is a coating on the lens. Creative WebCam NX Pro. Take a knife and scrape it off!

Night Vision Camera
Skanky page showing how to modify a webcam that has the IR filter inside the lens assembly (between two of the glass lenses).

 



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