In 1972, the U.S. proclaimed a contiguous zone extending from 3 to 12 miles offshore (Department of State Public Notice 358, 37 Fed. Reg. 11906 (June 15, 1972), consistent with the 1958 UN Convention on the Territorial Sea and Contiguous Zone.
The aperture of a lens is the opening in the diaphragm that controls how much light is allowed to reach your focal plane (film or sensor). The aperture is usually rated as a fraction of the focal length, hence the f/x.y nomenclature. The wider an aperture is, the more light it allows through, and the smaller the number under f/ is.
Depth of Field. Depth of field is a photography term that refers to how much of the image is in focus. The camera will focus on one distance, but thereâs a range of distance in front and behind that point that stays sharpâthatâs depth of field. Portraits often have a soft, unfocused backgroundâthis is a shallow depth of field.