Academy Aperture definition
Also known as Full Academy Aperture. This is a full frame that is exposed by the camera. It is used in 35mm with an aspect ratio of 1.33. There exists a mask in the projector’s gate that allows the changing of the aspect ratio to 1.85 or 1.66 when the film is projected. This crops the bottom and top of the image. Older films should be projected without the mask because they were never intended to be masked in the first place.