Glossary

This is a growing glossary of common camera terms. Feel free to add items that aren't listed.

• 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
• auto exposure
• center-weighted
• 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"
• diopter - an optical adjustment that allows someone to adjust the viewfinder's magnification to their vision
• f-stop - the measure of the aperture setting on a lens
• field of view - the diagonal measure of the part of a scene that is visible with a given lens
• film advance
• 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
• large format - a film format larger than medium format, in which negatives are loaded one at a time rather than in rolls
• lens - one or more glass elements used to focus an image onto the focal plane
• light meter - a device that measures light to determine the proper exposure settings for a scene
• medium format - a film format larger than 35mm but smaller than large format (typically 120 film) wound onto spools
• mirror lockup - a feature on some SLRs that allows the reflex mirror to be locked in the up position to eliminate vibration
• 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
• point-and-shoot - camera designed to eliminate the user's need to make focus and exposure settings
• QL - a Canon designation for film cameras using their "quick loading" feature
• rangefinder base - a measure of distance between the viewfinder and rangefinder windows on a rangefinder camera
• shutter curtain
• shutter release - the mechanism (usually a button) that causes the shutter to open and close
• SLR - single lens reflex
• TLR - twin lens reflex
• toy camera - an inexpensive camera usually made almost entirely out of plastic
• TTL - through the lens
• viewfinder - the part of a camera you look through when composing your shot