2 Pack 6-inch Crystal Optical Glass Triangular Prism for Photography, Kids, Science, Teaching Light Spectrum, Physics and Taking Photos Pictures (Set of 2, 150mm)

These are exactly as advertised. High quality glass in particular. I used these in a high school physics class, passing them around. My students loved them and played looking through them and projecting light on the walls. In this way they learned about refraction, different individual bands of wave length and color perception.

I bought them for photography and can't use any of them. I give them to the kids to play with. You can't even get a rainbow out of them.

Good and heavy - robust

I love prisms, and I have no idea why I waited nearly 60 years before buying myself a couple. Anyway, this is a lovely set of four prisms to get you started on imaging and the way light bends around various glass shapes. There's a triangle prism, which splits light into colors; a cube; a pyramid; and a crystal ball, which lets you pretend you can tell the future (and see reflections of images upside down!). As you can tell, I haven't had a chance to completely explore all the shapes of prisms. My only concerning item is that these things concentrate light, so you need to make sure they aren't in a place where they could start a fire (or are in their box when you aren't using them). They're also really heavy for their size: we have a slightly "slow" terrier who thought that knocking them off the windowsill would be a lot of fun. The mom in me says, "It's always fun until someone gets hurt." (The dog nearly knocked his own head off when the sphere came off the windowsill!) It is a lot of fun, and I'm thrilled to have it.

Bought to use for experiments in the Physics unit with my Grade 8 class. Great quality for the price. Prisms refract sunlight well and all students were able to see a rainbow.