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)

I tutor a 14 year old boy in the eighth grade. His science class is very weak so I purchased these prisms to illustrate refraction of sunlight. I stood with the Sun behind me, put the prism over my shoulder and directed the spectral display onto the shadow in front of me. It was beautiful- Violet, Blue , green,yellow, red.Note- these things are glass and the corners are very fragile. Don't just toss them around they will chip easily.

My preschooler and I enjoy experimenting with these. The prisms are good quality and arrived promptly. They are also a nice size and easy for little ones to hold.

My kid loves being able to see the rainbow with these.

I bought these to see if they would be good for teaching about prisms. Particularly about refraction of light. But if you look at the reflection of a line, or look through the prism at a straight line. (I used the edge of the white background on this screen) you will see that the whole is curved and not straight. The colors spread out as they should - but the whole line is curved - STRONGLY.So I think they took hot glass and forced it into a mold at the lowest temperature possible. Then polished the surface. So what happens (pretty sure) is the optical properties change from one end of the prism to the other.These are CHEAP. They have the right shape. They are clean. They will more or less refract single rays of light and spread out a beam of light for verbal demonstrations.Would this be a good starting point for any quantitative experiment - I don't think so. Unless you were teaching modeling and calibration. Then, the fun is taking a really badly made device (a prism is an optical device) - measure it, model everything, and then use the computer to standardize the poorly made device. Use measurement and computers to fix the too quick way they made this.I think all they need to do is heat the glass to a higher temperature, and be careful to cool it uniformly. I think these guys sell short prisms. I will see if the short ones are not so distorted.Such a curvature could come from strain left in the glass. But it can be a slowly varying index of refraction. If you were teaching gradient index things, it might be a good example. Ask the students to use the gradients for something practical.Hold the prism in two hands with the triangular shape pointing up. Look through the top (thin part) of the prism at the bottom of the computer screen. Slowly lift the prism until you can see the bottom of the screen. The line of your eye through the prism will be pointing above the screen.It should be fuzzy with the colors spread out. Notice how strongly it curves from one side of the prism (right to left, left to right)Hold the prism vertically, and turn it slowly around the vertical axis. Look for an image of the edge of the screen. It should have vivid colors. BUT it won't be a straight line. In mine, the apparent distance of the "straight" edge of the screen from long axis of the prism changes from top to bottom and is also curved. Wish I could show you. Will see if I can find a camera somewhere.Richard

Good value simple science project

Got for 6 year old after watching the magic school bus. He was impressed.

A google search informed me that to use a prism indoors to make rainbows you need incandescent rather than LED lights. So I also bought some incandescent bulbs for the first time in a very long time. And it still doesn’t produce rainbows.Returning.

Came in quick as expected, seller description is accurate, easily worth the price. Quality is very good too! Thanks!