Photographic Dictionary, A to L.
A prefix meaning “not” as in Asymetrical Asphericala,
ADAPTION: A process by which a person’s visual perceptual system adjust to altered stimulas situations, such as high or low levels of illuminations or a predominance of one hue.
ABERATION: In geometrical optics, a central term for failure of a lense to produce a theoretically perfect image of a point.
AMBIGOUS FIGURE: In visual perception, an image that can be interpreted by the viewer in more than one way with respect to the physical reality represented.
A PERTURE: An opening in a plate, located close to the film plane of a camera or projector that delimits the area of illumination.
ARCHIVAL: A process applied to processed images that are expected to remain relatively unchanged over long periods.
ARROW ILLUSION: The false perception that a straight line which is capped at both ends with outward slanting lines.
ARTISTIC: Applied to a subject or an image or a related factor, (E.G. arrangement, lightening, cropping), possessing qualities that induce in the viewer an impression.
ATMOSPHERE: A quality in a photograph that produces a distinct emotional response in the viewer. Large dark shadow area, I.E. creates a feeling of suspense. Syn: mood
ATTITUDE: The orientation of a camera axis or film plane with respect to the earth.
AMBIENT LIGHT: Light that is encountered at the scene, as distinct from that which the photographer provides by strobes, or other artificial means.
Obsolescent symbols for luminance.
BACKGROUND: The perceptual field in which a stimulus under consideration is located; also known as the surround.
BALANCE: A compositional factor involving an analogy between distribution of psychological weights in photographs and husical weights on a beam at varying distances from the fulcrum.
BENHAM TOP: A pattern of black and white arcs, when the pattern is rotated hues are seen.
BINOCULAR FUSION: The combining of images formed by the eyes so that the viewer perceives a single rather than duel objects.
BLACK LIGHT: A misnomer for ultraviolet (rarely infrared) radiation, since light is by definition visually effective radiation, black light in this sense does not exist.
BLUE: A color which corresponds to the 400-500 nano meter wave length region of the spectrum and which can be produced by removing the red and green components of white light.
BOUNCE LIGHT: Diffuse illumination produced by aiming a light source at a reflecting surface rather than at subject.
BRIGHTNESS: (B) The subjective aspect of visual perception that is approximately correlated with the luminance of objects seen as light sources.
BRIGHTNESS RANGE: Commonly used by photographers, the ratio of luminance for the lightest and darkest areas of a scene.
BRIGHTNESS VALUE: (Bv) An integer that represent the luminance level in the additive system of photographic exposure, which see.
BRILLANCE: A quality attributed to an image that is perceived as having a large range of tones and bright highlight areas. Usually with strong graduation.
BURN-IN: To give selected areas of an image, typically an enlargement, additional exposure, so as to alter the density locally.
BUSY: Said of a photograph of many objects or tonal areas where the arrangement tends to be unorganized.
BUTTERFLY LIGHTING: A type of portrait lighting, in which the main light is positioned directly in front of, and somewhat above the subject, there by projecting the nose shadow straight down onto the upper lip.
Bv: Luminance value, an integer that represents the luminance of the subject expressed in logarithmic terms in the additive system of photographic exposure (Apex).
The velocity of light which is approximately __________ meters per second in free space.
CALIBRATE: To determine, check, or correct the graduation of an instrument scale.
CAMERA: A light tight apparatus containing a lens or (pin hole) to form images on photo sensitive materials for the purpose of making photographs.
CAMERA EXPOSURE: Applied to time and relative apertures settings used to control the quality of light or radiant energy received by the photo sensitive material in a camera, E.G., 1/100 second at F/16.
CAMERA OBSCURA: A light-tight room with a lens or small aperture on one wall that forms images on the opposite wall.
cds: Cadmium sulfide cell.
CHROMATIC THRESHOLD: In visual perception, the minimum intensity of a light stimulus at which hue become apparent .
CIRCLE OF CONFUSSION: The out-of-focus image formed by a lens of a lens of an object point; specifically, the diameter of the circular image.
CLOSED DOWN: To change the F-number on a lens to a selected F-number that represents a smaller diaphragm opening.
COHERENCE: Degree of agreement of light waves with respect to phrase.
COLLAGE: A composite picture made by pasting a number of images on a support, generally abstract in nature.
COLOR: That aspect of visual perception associated with the attributes of light identified as hue, saturation, and brightness.
COLORIST: A person who applies dyes, paints, or other colorants to existing images.
COLORLESS: Without color, as air. Without hue; gray, white, black. Relative weak in hue; unsaturated.
COLOR NEGATIVE: A photographic image in which light subjects tones are reproduced as dark and vice versa, and subject colors are reduced as complementary colors; E.G., A blue object recorded as yellow.
COLOR PAPER: Photosensitive material on a paper base for making color prints from color negatives or color transparencies.
COLOR PRINT: A photographic color image made from another image rather than directly from the subject.
COMPOSITE: A photograph on which two or more separate images have been combined by any camera, printing, or post-printing technique.
COMPOSITION: The arrangement of visual elements in a photograph or other image with respect to effectiveness of the whole image.
CONTRAST GRADES: Numbers applied to photographic printing papers as an indication (in inverse order) of their exposure scales.
COPY RIGHT: The exclusive rights, granted by law, to the production, control and disposal of copies of photographs.
CORNEA: The normal transparent membrane which covers the front of the human eye.
CROP: To alter the boundaries of an image.
CROSS LIGHTING: Illuminating a subject from the side.
CYCLE: The maximum segment of a wave (light, electric, sound) before repition occurs, as from one crest to an adjacent crest.
LETTER D: the measure of the photographic effect in logarithmic rhythmic terms.
DENSITY: A logarithmic measure of light absorbing characteristics of an image, filter, etc. The ratio of light falling on and transmitted by the sample. That is D=log
DEPTH: The distance in a scene, measured parallel to the direction of view, or the perception of that distance in an image.
DEPTH OF FOOL: The range of object distance within which objects are imaged with acceptable sharpness.
DEPTH OF FOCUS: The distance the film plane can be moved before the image of an object point appears un-sharp as viewed on the photograph at the normal viewing distance.
DERIVATION: Any of various special effects achieved by abstracting one or more attributes from an original photograph, there by reducing realism.
DESIGN: An intentional arrangement of visual elements (live, color, texture) in a photograph or other image, with respect to the effectiveness of the whole image.
DEVELOPER: A substance used to convert a latent image on a photo-sensitive material into a visible image.
DEVIATION: In optics, the change in direction of a ray of light passing from one medium to another.
DIFFUSE: Applied to light has been scattered by reflection from a non-specular surface or by transmission through translucent material.
DIFFUSION: The process of scattering light.
D-LINE: Radiation having a wave length of 589.6 nano meters (NM). One of three waves lengths used n the computation of disperses power.
DODGE: To reduce the exposure in selected areas of an image to alter the density, E.G., by holding an opaque object between the lens and the easel in projection printing.
DOMINANT EYE: The eye that tends to determine the perception when images formed by two eyes fail to fuse.
DOUBLE EXPOSURE: The recording of two super imposed images on the same piece of photosensitive material. Either by or by design.
DRY MOUNTING: A process for permanently attaching photographs and similar material to a support using a heat-softenable adhesive tissue place between the print and the mount.
Dt: Transmission density
DW: Double weight
E: Internationally accepted symbol for luminance and irradiance.
EDUCATION: A teaching process designed to produce in an individual an appropriate degree of competence in one or more photographic subject areas.
EFFECTIVE EXPOSURE TIME: The time duration between the half open position and the half closed position of a leaf type shutter.
EFFICIENCY: Ratio of output to input.
ELECTRIC EYE: A photoelectric cell.
ELECTROMAGNETIC RADIATION: Energy propagated in wave form, including radio, infra red, light, ultra-violet, x-rays and gamma rays.
ELECTRO MAGNETIC SPECTRUM: The various forms of radiant energy arranged on a continuum in order increasing wave length from gamma rays to radio waves and including light.
EMULSION: A dispersion of silver halide crystals in gelatin or other suitable material.
ENLARGE MENT: Any image such as a photographic print, made by projection at a scale of reproduction larger than 1 to 1.
ENLARGER: An optical device containing a light source used to project images of negative or positive transparencies onto sensitized material.
EXHIBITION: A display of photographs for purpose, including education and the promotion of public relations or sales.
EXPOSURE: The act of allowing light or other radiant energy to fall on a photo sensitive material.
EXPOSURE TIME: The period that light or other radiant energy is allowed to fall on a photo sensitive material, measured in fractions of seconds.
LETTER F: Focal length.
f/: designation for f-number when expressed in numerical form E.G., f/16, f/8.
FADE: To lose quality in a finished image in the form of a change in density, contrast, or color.
FLUX: The rate of flow of energy, luminous flux is the rate of flow of light and is measured in lumens.
FOCAL LENGTH: The distance from the best axial focus of infinitely distance object to the rear nodal point of a lens.
FOCAL POINT: A position in image space that represents the image of an object point.
FOCUS: The place at which rays of light from an object point meet to form a minimum circle of confusion, or appear to form the sharpest image.
FOCUSING DISTANCE: Object distance; The linear separation of the subject from the front nodal plan of a lens.
FOG: Density in processed photosensitive materials that is not attributable to the action of image-forming radiant energy.
FORM: The surface configuration of an object or its representation in an image.
FRONT NODAL POINT: For an undeviated ray of light. The intersection of the entering ray with the lens optical axis.
FUSION: The perceptual blending of separate images or other stimuli.
GALLERY: An area devoted to the exhibition of photographs or other images or objects, especially works of art.
GANG: An arrangement of a number of negatives or other images combined for the purpose of being produced simultaneously.
GELATIN: A colloidal protein obtained by processing skins, bones, and other selected parts of an animal.
GENRE PHOTOGRAPHY: The specialization of making photographs of scenes from daily life.
GLARE: Intense light.
GOLD TONE: Applied to a photographic print that has been treated in a toning bath containing a gold compound, such as gold chloride.
GRADATION: Change in tone, texture.
GRAIN: A silver halide crystal in a photographic emulsion.
GRAY: Any tone between white and black, in lightness and without noticeable hue.
GRAY CARD: A neutral color cardboard, typically having 18% reflectance.
GRAY SCALE: A series of neutral tones arranged in sequence from light to dark.
GREEN: A color that corresponds to the 500-600 nano meters wave length region of the visible spectrum and that can be produced by removing the red and blue components from white light.
GUIDE NUMBER: A numerical value used to obtain a desired exposure effect when making photographs with a flash source.
LETTER H: The symbol for photographic exposure.
HARMNIC: A wave having a length 1/2, 1/3, 1/4, that of another wave.
HETER CHROMATIC: Of more than one color.
HIGH KEY: applied to a subject or image in which most tones are light.
HUE: An attribute of color that varies with the wave length composition of the light and is associated with names such as red, green, blue, cyan, magenta, yellow, orange, and greenish yellow.
HUNTER SYSTEM: A system of color notation based on the three attributes: hue, saturation and darkness.
HYPER FOCAL: The nearest object point that is imaged with acceptable sharpness when a lens is focused on infinity or the nearest object point that can be focused on while imaging objects approaching infinity with acceptable sharpness.
HYPO: A common name for sodium thiosulfite, a fixing agent.
HZ: Hertz. Unit of frequency. Preferred to cycles per second.
LETTER I: Symbol for radiant intensity ____ or luminous intensity ____
ILLUMINANCE: (E) The measure of the strength of light received at a point of a receiving surface.
ILLUMINATION: The process by which a surface receives light.
ILLUSTRATION: A photographic image that supplements text, as in books, magazines and catalogs.
IMAGE: The intersection of the apparent intersection of light rays. The first is the real image, the second, virtual.
IMPERFECTION: In a silver halide crystal, a departure from complete regularity of the crystal structure.
IMPRESSIONISM: In art, a style emphasizing light and color as interpreted subjectively by the artist. As distinct from a realistic style with emphasis on detail.
IMPULSE: In visual perception, a pulse of light that the theoretically has no duration.
INCANDESCENCE: Emission of light (I.E. visible radiation) by objects that have been heated to a sufficiently high temperature, above, about 1000k.
INCIDENT: Identifying energy, especially light, falling on a surface, as contrasted with that reflected, transmitted, or emitted by a surface.
INDEX OF REFRACTION: Symbol:N) The numerical measure of the effect of a material on the velocity of light.
INDIRECT: In lighting, reflected light, as from walls, ceilings, flats, etc., near the subject.
INDUCED MOVEMENT: A visual effect whereby a small stationary object appears to move in the presence of a large moving object.
INERTIA: The exposure near the beginning of the straight line of the D-log, H (D-log E) curve, found at the intersection of the straight line with the vase + fog level.
INVERSE: Reciprocal, I.E., the relationship between two variables, by which as one increases, the other decreases proportionally.
INVERSE SQUARES LAW: At a point on a surface receiving radiation from a point source. The Irradiance diminished as the square of the distance from the source is increased.
JIG: A device made to hold an object to be photographed.
JUNIOR: Slang for a medium spotlight.
LETTER K: (Formerly, Kº) Kelvin. A temperature scale based on absolute zero, and used for the specification of the color of some light sources.
LARGE FORMAT: Applied to a still camera that uses film size of 4x5 – inches or larger.
LATENT IMAGE: The image in a photo sensitive material, after exposure but before it is made visible and usable by development.
LATITUDE IN EXPOSURE: The permissible change in camera exposure, usually expressed in stops, without significant effect on image quality.
LENS SPEED: A measure of the caducity of a lens to admit light to the image.
LIGHT: Energy that can evoke a human visual response.