abstract: An appealing and edgy photographic style that uncovers and highlights the forms and contrasts in real objects.

aliasing: Aliasing, also known as moiré fringing, describes the step-like edges that diagonal or rounded lines take on in digital images. This jaggedness results from the square shape of the individual pixels that compose an image. When a picture has been aliased, it appears distorted with rough edges.

ambient light: Ambient light refers to any light in a given scene that isn't artificial light supplied by the photographer. Sunlight, candlelight or light emanating from surrounding lamps can produce ambient light in a photograph.

American Standards Association (ASA): The American Standards Association (ASA) refers to an antiquated scale for film speeds worked out by Kodak during the 1940s. Today, ASA film speed measures have been replaced by the ISO (International Organization for Standardization) standard that includes both linear and logarithmic dimensions.

angle of view: Angle of view, the amount of a scene that a photograph captures, can be measured vertically, horizontally or diagonally. Also known as angle of coverage or field of view, angle of view changes given the type of lens a photographer uses to take a picture.

Ansel Adams: Ansel Adams (1902-1984) was a photographer who is credited with devising the zone system technique (a method of concentrating light on negatives to control the look of finished pictures) and the theory of visualization (the act of measuring a scene's light to imagine a finished photo). Most famously known for his black-and-white photos of the Yosemite Valley in California, Ansel Adams authored many instructional books defining and developing his theories.

anti-aliasing: In contrast to aliasing (see above), anti-aliasing refers to refined edges in an image. The process of anti-aliasing calls for an exchange of colors within a pixel at the edge of the figure to smooth out the pixels. By blurring the colors at an image's edge, anti-aliasing produces crisper images.

aperture: Aperture refers to the lens diaphragm on a camera that controls the amount of light that touches the film when the shutter opens.

architectural photography: A popular art form that encompasses interior and exterior structures.

aspect ratio: Aspect ratio is a measurement of a photograph's width in relation to its height. Commonly, 35-mm film measures 36:24, creating an aspect ration of 3:2. Such an aspect ratio tends to produce 6"x4" printed pictures.

assemblage: A collection of photographs and also a collage style that incorporates several photos into one art piece.

astrophotography: A complex process of imaging the night sky through such techniques as time exposure.

autochrome: An early technique of combining grained filters to achieve color photographs.

autofocus (AF): Autofocus refers to a camera's ability to automatically adjust and focus its lens on a framed image. Cameras can come equipped with one of two types of autofocus systems: a passive autofocus or an active autofocus. While the passive mechanism uses sensors to detect contrasting light, active autofocus uses timed lasers to calculate the image's distance and then move the lens accordingly.

backdrop: A fabricated background, typically used in a studio setting.

backlighting: Backlighting refers to lighting in a photograph that comes from behind an object.
Because backlighting requires a subtle manipulation of a scene's light, photographers consider it a more advanced technique to master. However, when effectively implemented in a scene, backlighting can enhance the finer details of an object (such as the tiny hairs on bug) or the more delicate features of a scene (such as the dust particles or drops of mist in a given background).

bit-mapped: Bit-mapped refers to the way in which images are reproduced in a grid of dots, known as pixels. Each pixel within a bit-mapped image is a distinctive shade of black, white or grey. Consequently, when all of the pixels are lined up, they can reproduce the image on a macro scale.

bokeh: Bokeh is a technique of blurring an image to add to the aesthetic quality of a photograph. The word bokeh, derived from the Japanese word "boke" (pronounced "bo-keh"), literally translates to fuzziness. When a photographer wants to make an image appear softer, he might use bokeh to put the object a bit out of focus without completely destroying the integrity of it.

bounce lighting: Bounce lighting, generally used in portrait photography, is lighting that bounces off a particular source (such as an umbrella, wall, etc.) to surround the central object with light. Through the use of bounce lighting, a photograph will have fewer shadows and softer lighting.

bracketing: Bracketing is a photographic technique in which photographers take a number of shots of the same image with different metered exposures.

cable release: A cable release is a mechanism attached to a camera to allow a photographer to snap photos from a distance.

camera obscura: Camera obscura, Latin for "dark room," refers to a dark box in which light rays from an object pass through a small hole or lens to produce the image on the plate or film contained within. When the light rays create the image within the camera obscura, the image is generated upside down.

candid shot: Spur-of-the-moment photography capturing people acting naturally and sometimes without their knowledge.

celebrity: The focus of many photographers, whether in obtaining candid shots or working to produce publicity stills.

clip art: Graphic images, designs and artwork in digital form that people can use, either for free or for a fee. Clip art can be obtained on disc or CD-ROM or can be downloaded from the Web.

color depth: Color depth refers to the number that a given pixel is assigned in a photograph.
The number that a pixel is assigned determines the color of the pixel. Color depth can render 16 million different colors (about as many as the human eye can discern) in a picture based on a 24-bit-per-pixel measurement.

color systems: Color systems are systems that abstractly represent colors as numbers. In simple terms, the color space determines the colors that will be visible in a given photograph.

color temperature: Color temperature, a term borrowed from physics, is the measurement of a color's intensity on a scale of blue to red. In broad terms, color temperature refers to the visible light an object radiates based on its inherent heat.

color wheel: A color wheel is a diagram that maps colors by their relationship to the other colors on the circle. While colors that are related to each other are placed side-by-side, complementary colors (colors that are inversely related to each other) are put on directly opposite sides of the color wheel.

combat photography: The practice of taking pictures of soldiers in wartime.

commission: In photography, the act of accepting a job from a client; in other words, the artist is commissioned by the client to perform a job.

composition: The practice of composing a scene that involves analyzing angles, lighting and number of objects in the foreground and background.

compression: Compression refers to the process of reducing an image's file size so that it doesn't take up too much of a computer's memory. All digital cameras use some form of compression due to their limited storage capacity.

contre-jour: Contre-jour, a French word meaning "against the light," refers to the manner of taking a photograph with the camera more or less facing the light source.

cropping: Cropping is the process of cutting part of an image out of a picture to make the final photograph fit within a given space. When a picture is cropped, it isn't enlarged but, rather, maintains its original dimensions.

cut-out: In traditional photography, this involves shooting a subject against a white background so it can be trimmed for print layout. In digital photography, the process is achieved with software.

cyanotype: Cyanotype photography refers to the process of printing a picture by using sunlight and a series of chemicals. Cyanotype is not only cost effective, but it also serves as an effective alternative to a darkroom.

darkroom: A darkroom is the room that photographers use to develop their pictures. As the name suggests, the room is kept completely dark and, at most, only contains a safelight.

depth of field: Depth of field refers to the distance around an object that appears in focus in the frame or photograph.

depth of focus: Depth of focus measures the displacement of film within a camera. Also known as lens-to-film tolerance, depth of focus is measured microscopically (in thousandths of an inch, for example). Although this term has been interchangeable with depth of field in the past, depth of focus refers to the image placement on film within the lens, rather than the distance of the object from the lens.

Diana camera: A Diana camera, also known as a toy camera, is an inexpensive, low-quality camera. Housed in a plastic body, the traditional Diana camera was made in Hong Kong during the 1960s and 1970s.

digiscoping: Digiscoping is a method of taking photographs using a digital camera along with a spotting scope. Digiscoping is often used for wildlife shots or in other situations in which the photographer has to telescope the object being photographed.

digital manipulation: Digital manipulation refers to the process of digitally doctoring a photograph to alter the original image.

distortion: A subject in photos may be distorted, either on purpose or by use of specific lenses. Barrel distortion means lines bow outward while pincushion distortion adds concave curves to straight lines.

documentary photography: Documentary photography refers to the area of photography in which pictures are used as historical documents. Rather than serving as a source of art or aesthetic pleasure, documentary photography is often used to incite political and social change.

documentary: Realistic storytelling in a series of photographic forms.

double exposure: Double exposure refers to the technique of imposing two images into a singe space, either by taking two pictures on a single frame of film or printing two different images onto the same piece of photo paper.

DPI (dots per inch): Dots per inch (DPI) is a measurement of resolution that refers to the number of dots a printed photo contains per square inch of space. The higher the DPI, the higher the resolution.

enlarger: An enlarger is a projector that a developer uses to project a negative onto photographic paper in an enlarged form. Housed in the darkroom where film is developed, an enlarger contains a lens, a light and a cartridge to hold negatives.

erotic photography: Using nude or physically explicit subjects for photographs designed to arouse the senses.

exhibition: A show of a group or individual's works of art or photography.

exposure: Exposure refers to the amount of light that is exposed to the film in a camera when a photograph is taken. When the film is properly exposed, the right amount of light has hit the film for the correct amount of time.