Rainbow SymphonyDiffraction Grating Slides, Linear, 1000 Line/Millimeters, Made in USA, Package of 200

There's a potential for confusion regarding how this product works. This is a "single axis" diffraction grating which means you'll see the point source of light ... and you'll see the rainbow "smear" of the color spectrum produced by that light which will appear both left and right of the point source. Hence the name "linear" diffraction grating because it's all in a nice line. However, you WILL need to hold this VERY close to your eye (perhaps an inch or so away) and will still likely need to look out to one side to see the spectrum. That's just the physics of how the prisms are working - not a product defect.One other caution... avoid touching the film with your fingers (or anything else that might leave any oily residue behind). The gratings are basically a 1000 tiny prisms in every inch. If you touch the film, your fingerprint oils will fill in the gaps between each micro-prism and that will prevent the light from being diffracted correctly.I use these to do explain spectroscopy when doing science outreach. In my case I start with an ordinary tungsten filament light bulb, but then switch to using gas tubes with various gas elements (hydrogen, helium, etc.)

Bought these to hand them out as nice little gifts for people because I thought they were cool and that people would appreciate them. Only one person accepted it as a gift, now I have a stack of them. They work, and I think they are really cool, but I guess I might be the only one.

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.

These gratings work well. I received 25 gratings as advertised. and I'm glad I did. I only needed a few gratings for DIY spectrometer I was making. 4 or 5 of these gratings had either some nasty fingerprints or some sort of dust/dirt. The rest of the 20 were acceptable. I saw some other offers for a little less money but only for 10 gratings. The rejection rate is high but if you receive 20 out of 25 usable ones it was just fine with me

I purchased these actually as party favors for a science party and my toddler has since become fascinated by them. They function as expected and decompose various light sources into their appropriate spectra. Try looking through them at car headlights, smartphone screens, various lamps, pretty much anything illuminated.

The 1000 lines/mm diffraction grooves on these slides provide a large-angle dispersion in the spectrum -- about twice as much as typical gratings. That means that it is twice as easy to spot lines in the spectrum. Great product for the price, too.

These are a Hell of a lot better than you would think, especially considering the cost. Make Excellent spectroscopes.

We built take-home STEM kits for our students, and these grating slides were a perfect addition to our program's astronomy class. They are well-constructed and will "hopefully" hold up well to student use (they are students, so no guarantees!). The price was great, too!