Element 1 - Aperture and Depth of Field (DOF)

Aperture - An opening, in photography, the circular hole in the front of the camera lens which controls the amount of light allowed to pass on to the film from the lens. On all but very inexpensive cameras the size of the aperture is variable. The degree of variability is indicated by "i" numbers (f/stops). A great way to gain an understanding of apertures is to make and use a pinhole camera.