One of the cool things about real lenses is as I'm looking at a scene if I want too, I can just change, a little bit the focus in and out. Now for those of us who use cameras that just take pictures, our goal is to put something in focus or out of focus et cetera, whatever. If you're like Meghan, who thinks static pictures are just like way old school and the only thing that matters is video, then the idea of changing focus during video is interesting. Generates something that's called pulling focus or a focus pull, and you get this really cool effect. And here you can see this picture of this, pretty sure that's the Water Temple in San Francisco, somebody else might remember. And there's the back end, that's of a duck, but you can kind of see that it's shot through a fence. And as I run the video, you can see how changing focus changes where, how far in the scene, how far z has to be in order for it be in focus on the image plane. And that's pretty cool.