The cameras in after effects work in the same principles as real world cameras, including how they function with zooms and depth of field. So, what we'll do is, let's look at the custom drop-down menu and you can set your lenses so that you have a very wide angles lens at fifteen millimeters, or you can have a long lens which creates the sense of foreshortening, like telephoto lenses do, at two-hundred millimeters, and anywhere in between. And you can of course create your own zoom and your own custom camera, and then save it by clicking on this icon. So let's change this from fifty millimeters to two-hundred millimeters and you'll see that the angle of view shortens quite a bit. Now we have a very small angle of view, and this becomes particularly important. I'm going to change this back to fifty millimeters. This becomes very important when you want to enable depth of field and you do that by clicking here. Now once you enable depth of field, then you have to concern yourself with the aperture and the F stop, all of which have an influence on the depth of field, and just briefly for those who may not what depth of field is, depth of field is a function of camera that allows you to change or affect the focus of your image. So, there are three things that affect it, the amount of light, subject to camera distance, and the focal length of the lens. Those three things affect depth of field. And that's why those items, two of those items, the F stop and the focal length, are here in the camera setting's menu.
tech section
