Infragram DIY Filter Pack
A piece of blue and red filter which you can use to turn your webcam or cheap point-and-shoot into an infrared/visible compositing "multispectral" camera. The filter allows you to take an infrared photo in the "red" channel of your camera, and a visible image in the "blue" channel. These can be used to measure photosynthetic activity; read more about the technique at http://publiclab.org/near-infrared-camera and http://publiclab.org/infragram.
We are now offering packs with blue only filters! Find out more about red vs. blue filters and determine the best use for your work at https://publiclab.org/infragram-filters#Red+vs+Blue
Post-process your photos at Infragram.org , the free and open source image processing website which composites your images and helps you to assess plant health. See some example images at left.
Q&A
Installing your filter:
Be aware that this is a relatively permanent change to your camera -- you may not want to convert your expensive DSLR, for example! We've also found that not every webcam will produce good infrablue images -- while all the legit point & shoot cameras are fine, we're keeping track of which webcams do and don't work well on this page: http://publiclab.org/infragram-convertible-cameras (if you're doing your own experiments, as many already are, please add your findings there!) Additionally, we have discovered that a Rosco Red Fire filter works better for a larger variety of cameras and we have begun moving to produce red with blue filter packs.
(The lens assembly removed and the infrared-blocking filter being extracted. Typically the IR filter that needs to be removed is glued to the backside of the lens assembly.)