Photography Terms

	a composition rule that divides the screen into thirds horizontally and vertically, like a tic-tac toe grid placed over the picture on a television set. Almost all of the important information included in every shot is located at one of the four intersections of the horizontal and vertical lines
	A function or shooting mode of a semi-automatic camera that permits the photographer to preset the aperture and leaves the camera to automatically determine the correct shutter speed. What does that mean? You select the aperture setting you want and the camera then automatically calculates the appropriate corresponding shutter speed for proper exposure. It's like a fully-automatic camera except you totally control the aperture.
	Existing light surrounding a subject; the light that is illuminating a scene without any additional light supplied by the photographer. This is also called "available light".
	A shutter speed dial setting that indicates that the shutter will remain open as long as the release button is depressed - also known as the "B setting " or "Bulb" setting. The "B" setting is used for time exposures.
	Bokeh describes the rendition of out-of-focus points of light. Bokeh is different from sharpness. Sharpness is what happens at the point of best focus. Bokeh is what happens away from the point of best focus. Bokeh describes the appearance, or "feel," of out-of-focus areas. Bokeh is not how far something is out-of-focus, bokeh is the character of whatever blur is there.
	In a studio, the main light is placed fairly high, directly in front of the face - aimed at the center of the nose. It casts a shadow shaped like a butterfly beneath the nose.
	a lighting technique that is sometimes used in studio portrait photography. It can be achieved using one light and a reflector, or two lights, and is popular because it is capable of producing images which appear both natural and compelling with a minimum of equipment. Rembrandt lighting is characterized by an illuminated triangle under the eye of the subject, on the less illuminated side of the face. It is named for the Dutch painter Rembrandt, who often used this type of lighting.
	Sometimes called camera raw, raw format, raw image format and raw. A digital image storage format that contains the most information possible from a camera's sensor. RAW data ( a RAW image file) is unprocessed. Some folks consider it to be the digital equivalent of a negative or a slide.
	CMYK - An acronym for the ink colors Cyan (process blue), Magenta (process red), Yellow and Black used in four-color process printing.
	The primary colors of light (not of the inks used in printing) are red, green and blue, known by the acronym RGB.
	A complementary color is one of a pair of primary or secondary colors that are in opposition to each other on a color wheel.
	The range of distance in a scene that appears to be in focus and will be reproduced as being acceptably sharp in an image. Depth of field is controlled by the lens aperture, and extends for a distance in front of and behind the point on which the lens is focused.
	Digital single lens reflex camera
	Exchangeable Image File Format. Data produced by a digital camera that becomes attached to each image made by the camera, including make & model of camera, date & time, image format (e.g. jpeg, tiff, etc.)and dimensions, color & exposure modes, shutter speed, aperture setting, sensitivity, focal length of lens, whether the flash was on or off, white balance, exposure bias, metering mode and camera orientation when the picture was taken.
	A lens aperture setting calibrated to an f-number
	Frames per second (fps) refers to the number of pictures that a camera is able to take in a second. A point-and-shoot camera typically shoots one or two pictures per second. Higher-end single lens reflex (SLR) cameras have much greater performance, as many as five or more frames per second.
	(Graphics Interchange Format) is a small image file format that supports transparency and is constrained to a maximum of 256 colors, generally making it a poor choice for your digital images. When it was created, most computer video cards were able to display no more than 256 colors. It is used mainly on the internet for graphic images that don't require subtle or gradual change in tones. It was created for viewing online images from the CompuServe network, and is also known as a "CompuServe GIF."
	The time an hour or less before the sun goes down and around fifteen minutes after the sun has set. Sunlight is usually warmer and more complimentary to skin tones at this time, and the angle of the light can provide depth to portraits and landscape photography. This quality of light is also sometimes referred to as "Photographer's light."
	Graininess occurs when clumps of individual grains are large and irregularly spaced out in the negative. They are visible to the naked eye in the finished print, particularly enlargements, as sand-like particles. When this occurs, the picture appears "grainy." Graininess in digital images is caused by "noise," which usually appears in shadow areas and is generally unwanted and unattractive. In digital images graininess is directly related to using high ISO setting, usually ISO 0f 1600 and above
	Also known as the "Kodak neutral test card," a gray card is an 8" X 10" (20 cm by 25.5 cm) card, about 1/8" thick, that is uniformly gray on one side. The gray side reflects precisely 18% of the white light that strikes it (corresponding to the calibration of a reflected-light meter). It is uniformly white on the other side, which reflects 90% of the light. This card is used to help a photographer color correct an image before making an image (by adjusting settings on the camera) and after by using the gray card as a "gray" setting in digital color correction.
	An image that is mainly made up of light tones, with relatively few mid-tones or shadows.
	When the lens is focused on infinity, the nearest point to the camera that is considered acceptably sharp is the Hyperfocal point. By focusing on the hyperfocal point, everything beyond it to infinity remains in acceptable focus, and objects halfway between the camera and the hyperfocal point will also be rendered acceptably sharp.
	Adding new pixels to a digital image between existing pixels. Interpolation software analyzes the adjacent pixels to create the new ones when enlarging an image file.
	Film speed or sensitivity is designated by a single, almost universally-accepted common system developed by the International Organization for Standardization which uses the initials "ISO" before the film-speed number or digital camera's sensitivity setting number - e.g. ISO 100. ISO and ASA are the same (ASA is an older term)
	An acronym for Joint Photographic Experts Group that describes an image file format standard in which the size of the file is reduced by compressing it. JPEG, with its 16.7 million colors, is well suited to compressing photographic images. A "JPEG" image file name carries the extension "jpg" - e.g. "portrait.jpg" Many people refer to an image in JPEG format as a "JPEG," pronounced "jay-peg".) This is known as a "lossy" format.
	The visible light spectrum is scientifically described in terms of color temperature, and is measured in degrees Kelvin (K). The range for Kelvin on a pro digital camera is approximately 2,000-10,000.. These K settings are the scientific numbers behind the presets of WB on your camera.
	An accessory that attaches as a collar to the front of a lens to prevent stray light from striking the surface of the lens, causing flare
	A form of image compression when saving the image that discards data from it. Saving a picture as a JPEG uses lossy compression.
	Occurs when saving a digital image file in a format that does not result in a loss of data. A TIFF and PSD documents are examples of lossless image formats
	Describes a mostly dark image, with few highlights.
	A lens with the ability to focus from infinity to extremely closely, allowing it to capture images of tiny objects in frame-filling, larger-than-life sizes.
	refers to a million pixels, and is used in describing the number of pixels that a digital device's image sensor has.
	A million bytes, abbreviated as MB, Mb and sometimes Mbyte. Technically and more precisely, it refers to 1,048,576 bytes. Digital images are often referred to in terms of their "size in Mb".
	A contract in which a model consents to the use of his or her images by the photographer or a third party. Sometimes referred to simply as a "release."
	An image of a single color in differing shades. A black and white or sepia-toned image is a monochrome. Another monochromatic image is the cyanotype, or blue-green image made popular in blueprints.
	Or, electronic noise. This is the grainy look you find in a digital image caused by image artifacts. It is usually noticeable in shadow areas, and generally produced when shooting in low light. Noise is almost always unwanted and unattractive.
	Lens with a focal length approximately equal to the diagonal of the film format or of a digital camera's image sensor. A scene viewed through a normal lens appears to have the same perspective as if it was being viewed "normally" without a lens, just the way your eye sees it. Most 35 mm cameras' normal lenses have a focal length of approximately 50 mm.
	Occurs when the photographer incrementally lights an otherwise darkened scene using a handheld flashlight or other small light source while the shutter remains open during a time exposure. The light is added to the scene in the manner of an artist using a "paintbrush of light".
	Technique that involves taking a picture while moving the camera at a relatively slow shutter speed. It is almost always used when tracking a moving object, such as a race car, as it travels across the film plane. When properly carried out, the object is rendered relatively sharply while its surroundings are blurred.
	an image file type created in Adobe PhotoShop that results in pictures that are viewable with Adobe Acrobat, so someone (Mac or PC-user) who doesn't have PhotoShop can still view the image. It is often used in forms creation and for documents that require their layout, fonts and images to appear unchanged from the original.
	is an image file type created in Adobe PhotoShop. It is uncompressed and contains data on editing that is done to the image. A PSD file is essentially PhotoShop's version of a TIFF file. It lets you save a picture you are working on with its layers, channels and other image-editing data intact. PSD files must be converted to another image file type before use.
	Occurs when an image editing program is used to change an image's size. Increasing an image's size requires the addition of new pixels and decreasing size removes pixels.
	Commonly abbreviated as "TTL". Refers to both exposure metering of the light passing through the lens (Through-the-lens metering, and TTL flash metering) and viewing a scene through the same lens that allows light to reach the sensor or the film (Through-the-lens focusing).
	Tagged Image File Format - A standard digital image format for bitmapped graphics in an uncompressed state. The image files are much larger than compressed files, but can be opened in all image-processing programs.
	a clear, neutral filter that absorbs ultraviolet radiation, with no effect on visible colors. The skylight filter is a UV filter with a pale rose tinge to it.
	A digital camera analyzes a scene using its white balance mode to determine areas that should be recorded as pure white. The camera adjusts the overall scene's color balance so that the areas meant to be reproduced as white in the picture will be white, thereby also adjusting all the other colors in the scene using the same color shift values, so that all color is accurately represented.
	A lens in which focal length is variable. Elements inside a zoom lens shift their positions, enabling the lens to change its focal length - in effect, providing one lens that has many focal lengths. (Also called a "Variable focus lens.")
	Any device used to reflect light onto a subject.
	A fall-off in brightness at the edges of an image, slide, or print. Can be caused by poor lens design, using a lens hood not matched to the lens, or attaching too many filters to the front of the lens. It can also be applied after the image is taken for a positive effect.
	If you're hand holding your camera, your shutter speed should not be slower than the reciprocal of your effective focal length (but not lower than 1/50th of a second) in order to avoid "camera shake," i.e. the blur that results from any slight movement of the camera during the capture of the image. NOTE: The reciprocal of a number is the multiplicative inverse of the number or, in other words, one divided by the number. For example, the reciprocal of 100 is 1/100.