 Okay. Hello, it's me right here. Rhett Lane, there was a request about how to make a the sunglasses video, the sunglasses analysis that I made. So what I used with that was a light like this. So it's a tubular light. I'm going to show you everything you need to take a picture to look at the spectrum of different things to set it up. I'm going to show you several different things. What I used was, I used this light and then I used this diffraction grating. This is 600 lines per millimeter, maybe. Let me just see if I can show you what that would look like just through the camera. If I have that on, the nice thing about this is because it's a line, it makes it nice. I'll show you why. Let me put this in front of the camera. There's the light. Oh, there. So you see right here that these colors, when all the colors come through the diffraction grating, the different colors have been different amounts, so you get this. If you put something nice and black right there, then you can see that really well, and that's what we're looking for. But you don't need a light like this. The thing is, let me show you what happens if I turn that light sideways. It doesn't work. This is even tilted like that. It's not going to work as well because now the colors are spread horizontally, but they can smear with each other, and you want them nice and distinct. That's what's nice about this line bulb right here, but you don't need that. Because sometimes you want to look at stuff that's not like that. The sun's not like that, and you should never look at the sun. So I have here, these are from Arbor Scientific, but you can get these in a lot of different places. I'll include a link in the web page. These are the same thing, really. It's just in glasses form. They're about a dollar a pair if you buy them in bulk or maybe even cheaper. But if I hold them up to the glasses, you can see the camera, you can see it does the same kind of thing. You can see these little splittings. It works the same way, and they're cheaper than that. Here's what I did to use these, and you don't need a line source. This is the box. Let me make sure I can see it. This is a box. What I did was I cut a hole right here, and I cut a hole right there. Then what you want to do is you want to make a slit so that the only light passes through is in a line. Then you can look through it on this end and you can see what happens with the glasses. I would take this and I would put that in there. You actually can't see it. You can see some lines in there. Actually, I'm pretty surprised that works. There you go. See how nice it is? It actually works a lot better than just the diffraction gradient by itself because of that nice slit. I'm impressed. Now what you do is I take whatever I want to look at. I put my little device there. Then I put my camera right up to the hole. Can you see that? Then I can take a picture. You want to look through the viewfinder and make sure it's lined up the way you want. Now what if I want to test some sunglasses? Well, I can just put the sunglasses right here and then only the light that makes it through the sunglasses will get to the camera and I can take a picture. When I did it, I made it as a video. The reason was that I didn't want to get confused which sunglasses which so I could say this is sunglasses A and I could put it in front of there and record it and then I could just take that one frame. You get a better quality image with a picture but, you know, so that's that. I wanted to show you this too. I can't remember where we got these but this is the same kind of thing. I guess it's from NASA. See it says right there. NASA. So this is basically the same thing. There's a slit right here and then there's a diffraction grating right there and it even says, let's see if I switch that, warning, do not look directly at the sun. Okay, but if I look through this and I look over here to the side. Let's see if I can do this without. Okay, there's looking through it and then looking to the side. There you can see the nice thing about this is that it also has these little markings on there so that you can measure the different, where the different wavelengths are. These are just lines and not complete colors because it's light reflecting off of the, from the fluorescent lights. So oops, let me turn that back on. And then you can open up the, see it's got a little scale that shows up right there and you can see that and measure and it's actually pretty cool. So this is the same thing. Just you can hold it and you can measure stuff and then it has some things on the back. Okay, so that's all you have to do. You just need some way of making a slit. You need your diffraction grating, a camera and then a light source and you can put stuff in front of that. Now how do you analyze it? I'm going to show you that in another video. I'll show you as a screen cast.