I am excited to read that one can now buy a near-infrared Raspberry Pi camera. The regular one can be modified to measure NIR light but the process is futzy and error prone. I destroyed 2 cameras trying to get the damn thing apart. This new camera has the NIR filter removed so one is set to go right from the start. Adafruit has them in stock (as of this morning but I’m fairly certain they will sell out quickly).
My efforts to build the RPi multispectral camera are now made much simpler: http://www.evobeach.com/2013/09/a-raspberry-pi-based-multispectral.html