Is one type of standard lens available. A pinhole lens is only 1/16th of one inch in diameter, so cameras with tiny pinhole lenses can easily be hidden for covert video surveillance applications. Cameras with this type of standard lens are typically referred to as pinhole cameras. Most of the pinhole lens cameras have a 3.7mm focal length to deliver a wide field of view.
A special lens with a very small objective lens which is able to gather light through a small opening of about º”, sometimes less. These lenses are generally physically longer than a normal lens of the same focal length and are available in manual and auto-iris configuration; some are also made in a right angle form. The “F” stop of these lenses will generally be two or more “F” stops slower than a lens of comparable focal length.