Rainbow Symphony Diffraction Grating Slides - Linear 1000 Line/Millimeters 25 Pack 01603-25 25

Amazing science for the money

These diffraction gratings are amazing little things. There are 1000 lines per millimeter, causing light to be separated into the various components, like a prism would do. They're great gifts for curious minds. I give them out to people at the checkstand often, just because. The irony is that if you buy a pack of 20, it only costs around ten bucks, where if you only buy a pack of ten, it costs 12 bucks. Very strange indeed.

These are great for understanding how lighting works. If you look at an incandescent light bulb through the slide and a little askance, you see a stretched out version of the light that looks like a rainbow. But if you look at a fluorescent source, you instead see multiple copies of the fixture in discrete colors (shades of red, green and blue) that reveal that the light comes from phosphors that emit these colors. Even if these lights claim to be "full spectrum", the actual spectrum is a discrete sampling of frequencies which together let us see as if the full spectrum were present. Various industrial lights, such as metal halide parking lot lights, have unique and identifiable spectrums. If you want to tell one type of light from another, these slide are infinitely more portable and cheaper than $5000 electronic meters! That said, people don't immediately get the knack of looking askance at a light through a slide. A fancy meter will work better for customer presentations.

While the items were received in good condition and seem to work as advertised but the film is loose in the holders. This causes the film to not be flat. I think if you cut the film and attached it to a microscope slide it might work for more precision work.

Colors are hard to see.

Inexpensive and accurate measure of light spectrum. Highly recommended.