It is often said that that “the lens is the eye of the camera.” This is true, in that light enters through and is controlled by the lens, and ultimately this light registers an image. However, there are many things that the human eye and human psychology of perception do automatically, which, on a lens, must be accomplished manually. Framing, focusing, and exposure are activities we rarely consciously think about with respect to our own eyes, but a lens requires us to deliberately set each of these functions; and with each we are presented with a range of possibilities that ultimately represent the creative potential of any lens and its contribution to the aesthetic palette of a filmmaker. Always keep in mind that when setting lens functions, there is often no absolute “right” choice; rather, you must find the appropriate settings for what you want to communicate. On every single shot, you get to decide, from a wide range of possibilities, the framing and visual perspective within the frame, how near or close things appear, how bright or dark your scene and subjects are, and what is or isn’t in focus. Knowing how lenses work will help you choose the right lens and the best settings to create expressive images. It is helpful to remember that the lens is much more than just the eye of the camera: it becomes the eyes of your audience.