 Hello, everyone, and welcome to Tips and Tricks, a boom, lockdown edition. We're at the end of week four, and I know it's been tough on us all. We've had to cobble together workstations and make do with whatever we can get our hands on. I know I could have never made it this far, if not for my new invisible friends who crawl out of the electrical sockets at night and make stop frame animations on my kitchen table. But I'm sure we all have had similar heartwarming experiences, so let's just get on with it. Today I'm going to share with you a couple of expressions that do two different things, but they're both based on the formula that describes the basic attributes of a camera. It takes into account the relationship between the camera aperture, which in our case will be the size of the action render, the focal length, and the field of view. As we can see, our field of view changes as we move our lens, changing our focal length. This is best defined with the formula tangent of one-half the field of view equals the focal length over one-half the aperture. So what might we do with this formula besides make this snazzy interactive graphic? Well, our first expression will use this formula to adjust the scale of our image in relation to the distance from the camera. To demonstrate, we have our three socially responsible helpers here. We have our go-getter, our middleman who is supporting his favorite local essential business, and the slacker holding up a lamppost. As we can see, they're all maintaining proper social distancing. But when we dolly our camera back and forth, it's obvious that they're all on the same image plane. To change this but still maintain the same visual size of each of the characters, we will copy the image and add a G-mask that isolates each and in the scale for each axis enter this expression. Notice the number 540 denotes one-half the height of the HD raster. Now in a side view, we can see the image fitting into the camera's field of view as I move it in z-space. But on the right, there's no apparent change because our visual size remains the same. We'll move our helpers back in space and when we dolly our camera back and forth, we see that they now move in perspective. Good one. When this is over, I'm going to get that guy one of those t-shirts that says it's always five o'clock somewhere in the world. Thanks, fellas. For our second example, we'll use the formula to lock our image to the camera. The inspiration for this one comes from a practical effect in which the camera and the stage are locked together on a gimbal. And I'm told we have a visual aid for this. Is it working? Yes. Yes, we do. Let's cut over to the props department. And here we have a recreation of the famous stage used to create the effect of Fred Astaire dancing on the ceiling in the movie The Royal Wedding. We have the camera, lights and stage all connected together and the talent remains gravity-bound as the unit is rotated. And we can see from the point of view of the camera that our talent defies gravity. To do this in the flame, we parent our image to the camera and in the axis position Z, we enter this expression. Again, 540 is one half the size of our camera aperture of 1080. This expression is useful if we need to make our background an image in order to take advantage of certain attributes like masking or making it a bicubic or a bilinear. We can change the parameters of the camera in either target or free mode, including the field of view and the image will remain fixed. As you can see here, we're swinging the camera around with the abandon of a wild monkey, but the image remains unchanged. So that's our tip for the day. Before we go, I'd like to give a special shout out. Is it still up? Can we cut back to it? Yes? Yes, okay. Let's give a shout out to our friends at Isolation Miniatures. They really came through for us on short notice and of course a very special thanks to our dear friend Mr. Moybridge for the generous donation of his cat for the evening. This seems like a metaphor for how we're all feeling about now. I'm Tim Farrell. You can call me any time. Just dial YTF at LostPlanet.com. Stay healthy, stay creative, and we'll see you next time.