Glossary of Digital Camera Terms

AD Converter - converts analog electrical signals to digital binary signals.

AF Assist Lamp - auto focus assist lamp illuminates the subject you are focusing on when shooting in low light conditions.

Ambient light – The natural light in a scene.

Autofocus - Ability of the camera to focus automatically

Angle of view - The amount of a scene that can be recorded by a particular lens; determined by the focal length of the lens.

Aperture – A small, circular opening inside the lens that can change in diameter to control the amount of light reaching the camera's sensor as a picture is taken.

Aspect ratio - The ratio between the width and height of an image or image sensor.

Barrel distortion - Image distortion produced when the position of the camera lens is at its widest angle.

Bracketing - Taking several shots of the same scene at different exposure settings to help ensure getting at least one well-exposed photo. Some digital cameras have automatic bracketing with exposure compensation feature.

Camera shake - Main cause of blurred images, caused by even a slight movement of the camera as it records an image.

Continuous mode - A camera mode that lets you take multiple photos in rapid sequence as you hold the shutter release button down. It is used to capture a series of images or to photograph a fast or unpredictably moving subject.

Depth-of-field (DOF) - Refers to how much of a photo is in focus when the camera is focused on the main subject.

Digital camera photo - A photo taken by a digital camera.

Digital zoom - A simulated zoom.

EXIF - Exchangeable Image File - Data that is stored in jpeg and TIFF image files, such as shutter speed, date and time, focal length, exposure compensation, metering pattern and if a flash was used a the time a photo was taken.

Exposure compensation - Increase or decrease the exposure an image from the exposure automatically selected by a camera metering system.

Exposure meter - Built-in digital camera meter that measures the amount of light when framing a photo and determines the best exposure. Matrix (Evaluative), Spot and Center-weighted are the main metering types; some digital cameras have all three.

Exposure values (EV) - Exposure Values are numbers that refer to various combinations of lens aperture and shutter speed. When bracketing a photo, decrease the EV if a scene will appear too light (over-exposed). Increase the value if a scene will look too dark (under-exposed).

Fill-in flash - Forces a flash to go off even in bright light; often used outside to soften dark areas or shadows. The camera will expose for the background first, and then add enough fill-flash to illuminate your subject. Fill-in flash is also known as forced flash or flash on.

Flash exposure compensation - Digital camera control that lets you adjust the amount of output from the flash. Increase or decrease the amount to lighten or darken the effect of the flash.

ISO (Sensitivity) - The number indicating the camera sensors sensitivity to light. The higher the sensitivity, the less light is needed to make an exposure (see noise).

Liquid Crystal Display (LCD) - Monitor on back of a digital camera that shows 100% of the view through the camera lens. Like a viewfinder, it can be used to preview a scene before taking a photo. The LCD also displays camera settings and can be used to review photos and videos saved to a memory card.

Metering system - Measures the amount of light when framing a photo and determines the best exposure. The main digital camera metering types are - Matrix (Evaluative), Spot and Center-weighted.

Megapixel - A megapixel is equal to one million pixels (picture elements). Digital images are made up of thousands of these tiny, tile-like picture elements.

Noise - Randomly-spaced speckles (pixels) that can appear in digital images shot at high ISO numbers. Noise results in a reduction of photo detail and clarity.

Optical zoom - A true zoom. The focal length of the lens extends and retracts so the lens itself magnifies an image. Whatever the focal length of the lens, image resolution stays the same. Optical zooms produce the best photo quality.

Overexposure - Improper exposure causing an image to look too light. There is a loss of detail in bright areas.

Saturation - The intensity, or vividness, of a color. Increasing saturation makes colors in photos look richer. The amount of saturation can be adjusted in some cameras. It can also be increased or decreased with image editing software.

Shutter lag - The delay that takes place between pressing the shutter-release button and the time a photo is actually taken. Shutter lag times vary from digital camera to digital camera.

Shutter-release button - the shutter-release button on a digital camera must be pressed in two steps to lock exposure and focus and to help prevent camera shake.

Underexposure - Improper exposure causing an image to look too dark. There is a loss of detail in dark areas.

White balance - Adjusts the brightest part of a scene so it appears white. How a digital camera records color is affected by the source of light.

Zoom lens - A lens that lets you change focal lengths on the fly.