Advanced Photo System: A new standard in consumer photography developed by Canon and four other System Developing Companies - Fuji, Kodak, Minolta and Nikon - based on a new film format and innovative film, camera and photofinishing technologies to provide the user simple loading, easy flexibility on print sizes and improved photo quality.

Aperture: The lens opening, which permits light to expose the film or the CCD on a digital camera. The aperture size is either fixed or adjustable, and is calibrated in F-stop numbers; the larger the number, the smaller the lens opening.

ASA (American Standards Association), ISO (International Standards Organization): Film ratings, expressed as a number indicating a film's sensitivity to light. The larger the number, the more sensitive and faster the film is. While traditional cameras don't have a specific ISO rating, digital cameras do as a way to express their sensitivity to light.

Autofocus TTL (through-the-lens): Allows the camera to automatically focus through the lens, rather than by moving the lens back and forth manually.

Contrast: The difference between elements in a photograph. Contrast can include the difference between light and dark areas, or a marked difference in colors.

Depth-of-field: The zone of in-focus elements, from front to back. Another way to put this is the range of distance that is acceptably sharp within a photograph. Depth-of field varies inversely with the aperture opening. In other words, a wide-open lens with an aperture of f/1.8 has little depth of field; if stopped down to f/16, almost everything from front to back will be sharply in focus.

Developer: A chemical solution that changes invisible images exposed on light-sensitive film or paper into a visible image.

Exposure: How light acts on a photographic material. Light intensity is controlled by the lens opening, while the duration is controlled by the shutter speed. A camera with autoexposure can automatically control the exposure. The same principle works with digital cameras where film is replaced by the CCD.

F-stop: The number assigned to a particular lens aperture (or opening) size.

Film: A piece of plastic with a light sensitive mixture spread on it.

Film processing: The process where chemicals remove the unexposed silver on the film, then fix or stop the developing process and stop the negative's sensitivity to light.

Film speed: The film's sensitivity to light. For example, an ISO 100 film requires twice as much light as an ISO 200 film.

Flash: An electronic device that produces a burst of light the consumer can use to produce more exposure on the film.

Focal length: The distance from the rear model plane of a lens to the focus when the lens is focused at the infinity position.

Focus: to adjust the distance between the lens and an image to make the image as sharp as possible.

Lens: One or more pieces of glass, specially shaped, arranged to bring together rays of light so they can be recorded on film or paper.

Macro lens: A lens that lets users take close-up photographs.

Negative: A reverse image in which shadows and dark areas of the photograph appear light, and in which light areas appear dark.

Range finder camera: A camera that uses a system of prisms and mirrors to bring an image in focus, even though the viewfinder (unlike an SLR) is separate from the lens. Also sometimes known as a lens-shutter or "point and shoot" camera.

Shutter: A mechanism in the camera that opens and closes to allow light to reach the film.

Shutter speed: The length of time the shutter remains open when the shutter release is activated, expressed in fractions of seconds.

SLR, or single-lens-reflex: A user looking through the viewfinder on this type of camera actually looks through the picture-taking lens, thanks to a series of mirrors and prisms within the camera.

Transparency: A positive photographic image, such as a slide, typically meant to be viewed by projection.

Wide-angle lens: A camera lens with a short focal length, such as 24mm or 28mm.

Zoom lens: A lens whose focal length can be continuously adjusted.