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 - The ability of any camera/lens to 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 not permanantly, directly fixed to any other element.
• E-TTL -
• exposure - The combination of shutter speed, aperture, film sensitivity, and light used to create a single photograph.
• 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 plane onto which light entering a lens is focused.
• fisheye
• 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 - In an SLR, firing of the flash at the moment when the front curtain is open.
• 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 - Any light, other than that focused through the lens, that gets inside of the camera body.
• 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 - A focusing mechanism in which two overlapping images are lined up on top of each other.
• rangefinder base - A measure of distance between the viewfinder and rangefinder windows on a rangefinder camera.
• rear curtain sync - In an SLR, firing of the flash at the moment before the rear curtain starts to close.
• 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.
• 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.