Teaching the spectra of visible light can be an engaging classroom activity, but it's always been challenging to find ways to go beyond simple passive demonstrations.
Hand-held diffraction "rainbow" foil (sometimes mounted in cardboard glasses) can be fun. But students often have difficulty even spotting the spectrum. "I can't see it!" is the common complaint. And because each student observes their own "private" spectrum, it can be difficult to draw them into a discussion about what they're seeing.
An exciting new way to augment, or even replace, rainbow foil activities is to display a live spectrum on a computer overhead projector. When you use the RSpec-Explorer video spectrometer system, everyone observes the same thing. Having a concrete example in front of the classroom makes teaching the material much easier. And you'll find that a live video captures the students' attention far more effectively than any other teaching aid we've used for this topic.