A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Lamp - The complete unit of an artificial light source, including filament or electrodes, bulb, base and other components.

Large format - Film format having individual frames of 4" X 5" or larger.

Latent image - Image recorded on film that is made visible by development.

Lateral reversal - A mirror image, as seen in the viewfinders of some cameras where the scene appears flipped from left to right.

Latitude - Commonly “Exposure latitude” - The range of brightness, including shadow detail, that a film can record in a single image before the highlights wash out or the shadows become muddy. Fast films generally have greater exposure latitude than slow films. Knowing a film’s latitude lets you know how much exposure can be varied and still produce an acceptable image.

Leader - The part of film at the beginning of a roll that will not be exposed to make an image but is used to attach the film to the camera’s take-up spool. 35mm film usually has a leader that is narrower than the rest of the roll - its shape originally designed for bottom-loading Leica cameras.

Lens - A true “lens” is a single piece of glass (or other transparent substance) having one or more curved surfaces used in changing the convergence of light rays. What we commonly call a photographic lens is more accurately and technically called an “objective,” an optical device containing a combination of lenses that receive light rays from an object and form an image on the focal plane. However, dictionaries have come to accept the usage of the term “lens” to mean the entire photographic objective itself. A photographic lens will always be called a lens, even though it is not a lens, but has a lot of lenses in it. A camera lens collects and focuses rays of light to form an image on film.

Lens hood - A simple lens accessory made of thin metal or rubber used to shield the lens from stray light that does not come from the subject and can impair the image.

Lens-shutter camera - A camera that has the shutter built into the lens itself.

Lens Speed - The widest aperture at which a lens can be set. A lens with a fast speed has a very wide maximum aperture, such as ƒ/1.4, for example, and transmits more light than a lens with a slow lens speed, such as ƒ/8.

Lightbox - A enclosure containing white-light balanced fluorescent tubes behind a flat translucent glass or plastic surface on which transparencies or negatives are laid in order to view them.

Lighting ratio - The brightness of the main light (key light) compared with the brightness of the fill light(s). A ratio of about 3:1 is normal for photography.

Light meter - An instrument used to measure the amount of light reflected from or falling on a subject. The measurement is usually expressed in shutter speed and aperture combinations that will render an acceptable exposure. (Also known as an "Exposure meter.")

Light tent - Translucent fabric attached to a frame that surrounds a subject. Typically used to reduce reflection from highly reflective subjects. The light source is outside the enclosure, but the lens pokes through a hole in the fabric.

Light-tight - Impervious to light

Light trail - A line recorded on film resulting from movement of a point of light (or camera movement) during the exposure. Star trails are one example.

Light trap - An opening through which light cannot penetrate, useful for ready access to a darkroom. Typically, the entrance is u-shaped, with a light baffle built down the opening of the “U”. A person walks around the baffle, which blocks light, to enter and exit.

Location - A photography site that is outside of the studio. The often-heard term "shooting on location" refers to taking pictures at such a site.

Long focus - A lens of relatively long focal length with a narrower angle of view than a normal lens, but with a more enlarged view of the scene.

Loupe - A small magnifying glass used in viewing transparencies (slides), negatives and contact sheets. Generally a loupe's magnification is eight times.

Low key - Describes a mostly dark image, with few highlights.

Luminosity - the brightness of a light source.