Digital Photography Glossary


Ambient(Available light): Ambient light refers to any source of light that is not explicitly supplied by the  photographer for the purpose of taking photos or surrounding light

Aperture:  refers to the opening of a lens's diaphragm through which light passes

ASA:  a rating of the speed of the film.

Backlighting: this describes the process of illuminating the subject from the back.

Burn In:  is the practice of darkening a certain area of a photograph print by exposing that area to more printing exposure.

Bit:  The smallest unit of computing information.

Bit depth (1-bit, 8-bit, 24-bit): The amount of information (black and white or color) a computer can discern for each bit of an image. 1-bit is black and white (off or on), 8-bit is 256 "shades", "values" or "levels" of gray or 256 colors, 24-bit is millions of colors.

Contrast: Contrast: is the difference between dark and light values.

Crop: Crop: To select out an area of an image. Once an image is cropped, save the cropped version with a different name, retaining the original image.

Density: Density: refers to the thickness of the silver found on paper or film. When a negative is over exposed there are known to be very dense with silver.

Depth of Field: Depth of Field: is the distance between the furthest and nearest points that are in sharp focus. You can adjust the depth of field by adjusting the length of the lens, the distance to the subject or the aperture size.

Digital image: Computer file which, when used in conjunction with the proper software, will display a picture on the computer screen or print out to a digital device such as a laser printer.

Dither: Dither: a way of arranging the dots in a digitized image that creates an optical illusion of more continuous colors or gray tones than the computer or device can actually display or print.

Downsize: Downsize: To reduce the file size of an image, by lowering the resolution and/or reducing the square measurement of the file.

Emulsion: Emulsion: the light sensitive coating that is put onto paper and photographic films.

F-stop: F-stop: this is the number that indicates how large your lens opening is.

File format: The specific way digital information is made and stored by the computer. Not all software applications can read and/or manipulate all file formats. (See: GIF, JPEG, TIFF.)

Flare: Flare: refers to when, in lenses, stray light or internal reflections cause a fogging effect or light streak marks on the film.

Grain: when the silver found inside of a negative is clumped together and photograph gives the “speckled’ appearance

GIF  (Graphics Interchange Format) : A common graphic file format on the World Wide Web; used by online services and Web browsing software, GIFs contain information compressed into a relatively small file size and may display faster than other formats.

Grayscale: Grayscale: A system of displaying images in gray tones (or "levels of gray"), simulating the continuous gray tones of a photograph. To achieve grayscale, a monitor must be able to display 2 to 16 bits of information per pixel. This allows the monitor to display a black or white pixel as well as several values between black and white.

High Contrast: Contrast: is the difference between light and dark in an image. High contrast  images will have bright highlights and dark shadows, bold colors, and show texture in the subject

ISO: ISO: stands for international standards organization and is a numerical rating that describes how sensitive film is to light. Image file size: The amount of computer storage space a file requires; usually measured in kilobytes (K) or megabytes (M, MB, mgs or "megs"). An image file that is 5 x 7 inches, 8-bit gray (as in a black and white photo), resolution 300dpi, is 3M in size. (A floppy disk holds 1.3M.)

Image size: The physical dimensions of the image as measured in the small squares (pixels) of a computer screen; an image filling a "typical" computer screen (13 inch diagonal) would be 640 x 480 pixels; compare to image file size above.

Overexposure: An image that is brighter than it should be considered  overexposed . When too much light is allowed during exposure, the result is an overly bright photograph.

JPEG : (Joint Photographic Experts group): Pronounced "JAY-peg", a graphic file format that compresses information about many colors (up to 16 million) in the image into a smaller file

Line art: Black and white art, usually some type of line drawing (such as that produced by pen and ink).

Panning: Panning: panning refers to a technique in which you pan your camera along in time with the moving subject and end up getting a relatively sharp subject but a blurred background.

Pixel: Short for picture element, pixels are the tiny components that capture the digital image data recorded by your camera. Pixels are also the individual components that collectively recreate the image captured with your digital camera on a computer monitor. The more pixels there are, the higher the screen or image resolution will be.

Reciprocity: also sometimes referred to as the reciprocity law. Reciprocity is the law of the relationship between shutter and aperture. It stipulates that one stop increases in aperture is equivalent to the shutter duration doubling. Both increase light by one stop.

Saturation: Saturation: It is used to describe the intensity of color in the image. A saturated  image has overly bright colors.

Stop Down: is the act of using a smaller lens opening.

Shutter Speed: Shutter Speed: also known as “exposure time”, stands for the length of time a camera shutter is open to expose light into the camera sensor.

Value: The lightness or darkness of a gray or a color. The darkest level or value of gray is black and the lightest level of gray is white.

Washed Out: It is used to describe slides that are overexposed.

Wide-Angle Lens: a lens that allows a wider view; usually around 35 to 24 mm of focal range.