Glossary

This is a growing glossary of common camera and photography terms. Feel free to add items that aren't listed by using the "edit" tab at the top of the screen.

• 35mm - A film format with frames measuring 24mm x 36mm on a roll of film wound into an easy-to-load cassette.
• aperture - An opening in a lens that limits the amount of light passing through it.
• aperture priority - A metering method which recommends a shutter speed based on a desired aperture.
• autofocus - describes any camera / lens that can focus itself electronically.
• auto exposure - an in-camera exposure system that attempts to set the aperture and shutter speed (and ISO in many digital cameras) to get the best exposure for the current lighting situation.
• Bay I - Bayonet type I. A type of filter mount commonly used on TLRs.
• Bay II - Bayonet type II. A type of filter mount used on some TLRs.
• center-weighted - an in-camera light-meter system that favors the center of the frame although it does take into account the rest of the frame to a lesser extent.
• click stops - See also detents.
• cable release - An attachment that screws into a shutter release that allows you to trip the shutter mechanically while being isolated from the camera.
• coated - See lens coating.
• contrast
• Compur
• Copal
• coupled rangefinder - A rangefinder that provides a focusing aid which is "coupled" to the focus adjustment on a lens.
• depth of field - The range of distances (from near to far) within which a scene will be considered to be "in focus."
• detents - Positions on a moving dial (eg, shutter speed or aperture dial) at which movement is locked.
• diopter - An optical adjustment that allows someone to adjust the viewfinder's magnification to their vision.
• element - An individual glass structure in a lens that is dot permanantly, directly fixed to any other element. In older lenses an element was an individual piece of glass but more modern lenses make use of some composite elements which are two or more pieces of glass cemmented together.
• exposure - The amount of light that enters a camera to create a single photograph. The exposure is composed of three things; shutter speed, aperture and film/sensor speed (ISO)
• f-stop - The measure of the aperture setting on a lens.
• field camera - A large format camera, slightly stripped down to make it more portable.
• field of view - The diagonal measure of the part of a scene that is visible with a given lens.
• film advance - Mechanism for moving the film from one spool to another, usually one frame at a time.
• film plane - the position of the light sensative material in a camera.
• flash sync - The manner by which a flash is fired while the shutter is open.
• focal plane - The flat plane onto which a lens focuses its image.
• focal plane shutter
• frame counter - A mechanism for recording the number of exposures made or for calculating the number of exposures remaining on a roll of film or memory card.
• front-curtain sync - when combining flash with a long exposure, front-curtain sync describes the action of the flash firing immediately after the shutter opens. This is the more common action.
• GOST - A measurement of film speed used in the former Soviet Union.
• large format - A film format larger than medium format, in which negatives are loaded one at a time rather than in rolls.
• leaf shutter - A type of shutter mechanism that uses small metal blades in a leaf pattern.
• Leica nipple
• lens - One or more glass elements used to focus an image onto the focal plane.
• lens barrel - The tube that contains the lens elements.
• lens coating - A coating applied to lenses that corrects color abnormalities in the glass, reduces flare (to some extent) and can protect exposed glass surfaces. All modern, mainstream lenses are coated.
• light leaks - Light, other than that of the exposure, that can spoil film while it is in the camera. Light leaks can show up as bright streaks or fogging on film and are often due to the deteriation of foam seals around a film door on older cameras or poor camera manufacturing standards on new cameras such as a Holga.
• light meter - A device that measures light to determine the proper exposure settings for a scene.
• lomography - movement that promotes (and exploits) the use of Lomo cameras (predominantly the LC-a) and a "shoot from the hip" attitude.
• medium format - A film format larger than 35mm but smaller than large format (typically 120 film) wound onto spools.
• metering - measuring the amount of light for an exposure.
• mirror lockup - A feature on some SLRs that allows the reflex mirror to be locked in the up position to eliminate vibration.
• mirror slap - The vibration caused by the mirror in an SLR flipping out of the way before a shot.
• multicoated - See lens coating.
• optical axis - The straight line which passes through the centers of curvature of the lens surfaces.
• parallax - An effect in photography where the image seen in the viewfinder is not the same as the image seen through the lens.
• parallax error - the diference between what the photographer sees and what the camera takes. This is most evident in close up work when using a viewfinder that does not look through the taking lens.
• point-and-shoot - Camera designed to eliminate the user's need to make focus and exposure settings.
• polarizer - A filter that only allows light with a specific orientation to pass through it.
• QL - A Canon designation for film cameras using their "quick loading" feature.
• rangefinder
• rangefinder base - A measure of distance between the viewfinder and rangefinder windows on a rangefinder camera.
• rear-curtain sync - when combining flash with a long exposure, rear-curtain sync describes the action of the flash firing just before the shutter closes. Front-curtain sync is the more common action.
• saturation
• self-timer - A mechanism built into the shutter release, used to release the shutter after a set period of time.
• selenium
• sharpness
• shutter curtain - most focal plane shutters are composed of two curtains; a front and rear curtain. The front curtain slides open to begin the exposure with the rear curtain sliding closed in the same direction to close the shutter.
• shutter lag - See also shutter latency.
• shutter latency - The delay between the moment the shutter release is pressed and the moment the shutter actually opens.
• shutter priority - A metering method which recommends an aperture based on a selected shutter speed.
• shutter release - The mechanism (usually a button) that causes the shutter to open and close.
• shutter speed - The amount of time the shutter remains open.
• SLR - "Single Lens Reflex."
• sunny-16 rule - A light metering guideline that says proper exposure on a sunny day is f/16 at a shutter speed that is the reciprocal of your film speed.
• TLR - "Twin Lens Reflex."
• toy camera - An inexpensive camera usually made almost entirely out of plastic (including the lens).
• trigger advance
• TTL - "Through the Lens."
• view camera - A large format camera that allows the geometric relationship between the film plane and the lens plane to be adjusted.
• viewfinder - The part of a camera you look through when composing your shot.
• viewfinder blackout - the time when the mirror in an SLR flips up to allow the film plane to be exposed during which the photographer cannot see anything through the viewfinder.