Photography Vocabulary Agitate- To move a solution over the surface of film or paper during development so that fresh liquid comes into contact with all surfaces. Aperture- The size of the lens opening through which light passes. Aperture-priority- A mode of automatic exposure in which the photographer gives priority to aperture and adjusts shutter speed accordingly. ISO/ASA- A film speed rating that describes the sensitivity to light of the film. It can also effect the grain of the film (in film photography). Automatic Focus- A system by which the lens automatically focuses on a given area. It’s abbreviated as AF. Back lighting- Lighting that comes from behind the subject. This can cause a silhouette effect on the subject being photographed. Bracket- To make several exposures, some greater and some less than the exposure calculated to be correct. Bracketing allows for error and permits selection of the best exposure. Burn- To darken a specific area of a print by giving it additional printing exposure. Camera- A picture-taking device, consisting of a light-tight box, a film holder (if it’s a film camera), a shutter to admit a measured quantity of light, and a lens to focus the image. Contact print (sometimes referred to as a contact sheet)- The process of placing a negative in contact with light sensitive paper, and then passing light through the negative on the the paper. The resulting image is the same size as the negative. Contrast- The difference in darkness or density between one tone and another. Contrast filter- A colored filter used that selectively absorbs some wavelengths of light passing though it. Crop- To trim the edges of an image, often to improve the composition. Cropping can be done by moving the camera position while viewing a scene, by adjusting the enlarger or easel during printing in the darkroom, by trimming the finished print, or by cropping a picture in a computer program (such as Photoshop for digital images). Darkroom- A room where photographs are developed and printed, sufficiently dark to handle light sensitive materials without causing unwanted exposure. Depth-of-Field- The area between the nearest and farthest points from the camera that are acceptably sharp in an image. Developer- A chemical solution that changes the invisible, latent image produced during exposure into a visible one. Dodge- To lighten an area of a print by shading it during part of the printing exposure. Easel- A holder to keep light-sensitive paper flat and in proper position. Emulsion- The light sensitive material that is on film and photographic paper. It consists of silver halide crystals and other chemicals suspended in gelatin. Enlargement- An image that is larger than the negative. It’s made by projecting an enlarged image of the negative onto light-sensitive paper. Enlarger- An optical instrument used to project an image of a negative onto light- sensitive paper. Film- The material used in a camera to record a photographic image. Its is made of light- sensitive emulsion that is flexible. Fixer- A chemical solution that makes a photographic images no longer sensitive to light. It dissolves unexposed silver halide crystals while leaving the developed silver image. F-stop- The common term for the aperture setting of a lens. Graininess- In an enlarged image, a speckled or mottled effect caused by over-sized clumps of silver in the negative. Manual exposure- A non-automatic mode of camera operation in which the photographer sets both the shutter speed and the aperture. Negative carrier- A frame that holds a negative flat in the enlarger. Photogram-An image formed by placing material directly onto a sheet of light-sensitive paper and then exposing it to light. Photomontage- A composite image made by assembling parts of several photographs together into one image. Safelight- A light used in the darkroom during printing to provide general illumination without giving unwanted exposure. They are often referred to as “red lights”. Shutter- A mechanism that opens and closes to admit light into a camera for a measured length of time. Shutter-priority- A mode of automatic exposure in which the photographer selects the shutter speed as the priority, and changes the aperture accordingly to create a properly exposed image. Solarization- A reversal of image tones that occurs when film is massively overexposed. This is usually done as an purposeful effect. Value- The relative lightness of darkness of an area. Low values are known to have “low contrast”, and high values are known to have “high contrast”. Viewfinder- A small window on the camera through which the subject is seen and framed. Wetting agent- A chemical solution used after washing film. It reduces water spots from forming..