Flashlight Enthusiast
Apr 12, 2001
Berkeley CA
http://spectralworkbench.org/analyze/spectrum/15780 ("BLF Mini" white LED flashlight)
http://spectralworkbench.org/analyze/spectrum/15779 (Arc AAA red-orange LED flashlight)
http://spectralworkbench.org/analyze/spectrum/15769 (Macbook Pro white LED backlight)

more to come.

Spectral Workbench is part of Public Lab www.publiclab.org

I felt lazy and interested in what's coming out of my various white LEDs (not to mention the bright white LED streetlights going in down the block)
so I paid $40 for their simple kit -- it's a board camera and cable with a USB plug, with a case (electrical hardware box), a light shield (cut-and-fold) with optical slit already cut for position, a piece of DVD (break off the colored part; the "transparent" layer has the fine lines, close enough to parallel out at the edge, to make a rainbow from a point source). Plus some tape and a wood block for getting the angle right. This is for making _transmission_ spectra, so the camera focuses through the plastic, rather than looking at the rainbow on the surface.

The software's online, changing fast, working well enough at this point to get results.