Fitting on the body of a camera that is designed to accept accessories and portable flash units.
In most lenses, the aperture is an adjustable circular hole centered on the lens axis. It is the part of the lens system that admits light.
In-camera metering system in which the photographer selects the aperture and the camera meter adjusts the shutter speed accordingly.
Camera system in which a photo-electric cell measures the light reflected from the scene and adjusts the amount allowed to reach the film.
Sensors within the camera body that judge the sharpness of a selected central part of the image. Servo-motors in special lenses adjust the focus accordingly.
Central processing unit. In an automatic camera, the part of the electronic circuitry that coordinates the programming.
Thin deposit on the surface of a lens designed to reduce flare through interference.
Lens constructed from two or more elements. Different shapes and curvatures make it possible to correct certain aberrations with a compound lens.
A replacement for the normal camera back, this prints date, time and other information onto a small area of the film, usually by means of fiber optics.
On-camera flash unit designed for use with a specific camera, linking directly with the camera's internal circuitry.
Numerical counter which updates as each picture is taken.
The standard way of describing the relative aperture of a lens. Calculated as the lens focal length, divided by its effective aperture. It makes it possible to compare the aperture settings of different lenses.
Lever used to advance the film to the next frame. On many automatic and point and shoot cameras, this is done automatically for the user. Many photographers, however, prefer to rewind the film manually.
The plane at the back of the camera in which the film lies and on which the image is focused.
The distance between the center of a lens (the principal point) and its focal point.
Moving this ring will adjust the elements inside a compound lens resulting in the image being soft or sharp.
Dial on a camera used to set the proper ISO/ASA film speed.
Arithmetically progressive rating of the sensitivity of film to light. Arithmetic ISO speeds are effectively identical to ASA.
Camera operation in which the photographer over-rides or by-passes the normal automatic systems such as metering and focus.
Through-the-lens (TTL) metering system in which the exposure is measured from different areas of the frame. The resulting pattern is compared to a library of images already analyzed and programmed into the camera.
Five-sided prism used in the viewing system of an SLR camera to turn the image right way up and right way round.
The various ways an automatic camera can be set to operate by the photographer so that different priorities can be selected.
A hinged mirror in the center of the light path which directs the image upwards into the viewfinder. The shutter release raises the mirror an instant before the shutter operates, allowing the light to fall directly on the film plane.
Twisting this knob in a clockwise motion will rewind, or tighten the film inside the camera. On many cameras lifting this knob will open the back of the camera.
A timer which has a built in delay prior to taking a picture. Several automatic cameras have the option of choosing a desired length of time for the delay.
Some automatic cameras allow the shutter speed to be set by the user. The camera then selects an aperture for the best exposure.
Pressing this button all the way down, results in a picture being taken.
Camera design that allows the image focused on the film plane to be previewed by a hinged mirror that diverts the light path. Also called SLR.
Through-the-lens metering. Exposure meter built into the camera, normally located close to the instant-return mirror of a single lens reflex or to the pentaprism.
Simple optical system used for viewing the subject.
