Digital Photography Glossary
Ambient light – The natural light in a scene or light in a room without using flash.
Archival – The ability of a material, including ink, print papers and compact discs, to last for many years.
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. The aperture diameter is expressed in f-stops; the lower the number, the larger the aperture. For instance, the aperture opening when set to f/2.8 is larger than at f/8. The aperture and shutter speed together control the total amount of light reaching the sensor. A larger aperture passes more light through to the sensor. Many cameras have an aperture priority mode that allows you to adjust the aperture to your own liking. See also shutter speed.
Aperture priority - a camera function that permits the photographer to set the aperture and the camera automatically determines the correct shutter speed.
Autofocus - ability of a lens to focus automatically on an object within its focusing sensors.
Automatic exposure - a mode of camera operation in which the camera automatically adjusts the aperture, shutter speed, or both for proper exposure
Back-lighting - light directed at the subject from behind the subject. This often causes the subject to be underexposed unless spot metering or exposure compensation is used.
Buffer – Memory in the camera that stores digital photos before they are written to the memory card.
Burst or Drive Mode - Many digital cameras have some type of burst or fast-shooting mode to take a series of photos in quick succession. The capability or performance will vary by camera or model. This is referred to as drive mode in SLRs.
Contrast – The difference between the darkest and lightest areas in a photo. The greater the difference, the higher the contrast.
Cropping - removing parts of an image in order to improve the image’s composition.
Depth of field - 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.
Download, downloading – The process of moving computer data from one location to another. Though the term is normally used to describe the transfer, or downloading, of data from the Internet, it is also used to describe the transfer of photos from a memory card to the computer. Example: I downloaded photos to my PC.
Exposure - the amount of light captured by the camera. Digital cameras feature auto exposure, sometimes known as programmed auto exposure, in which the camera reads the amount of light in the scene and then sets the exposure automatically for you.
Exposure compensation - deliberately changing the exposure settings recommended by the camera in order to obtain proper exposure. This is usually done in steps of 1/3 to 1/2 of an f stop.
Exposure/focus lock - the ability to point at one part of the scene and hold the shutter button half-way down to lock in exposure and focus settings then point the camera elsewhere to re-compose the scene.
EXIF – Exchangeable Image File: the file format used by most digital cameras. For example, when a typical camera is set to record a JPEG, it’s actually recording an EXIF file that uses JPEG compression to compress the photo data within the file. EXIF records all the settings your camera uses when taking a picture so you can check it in Elements or image-viewing programs to see it.
External flash – A supplementary flash unit that connects to the camera with a cable or hot shoe, or is triggered by the light from the camera’s internal flash. Many fun and creative effects can be created with external flash. Also referred to as Speedlites or Speedlights by Canon and Nikon.
f stop - an adjustment which changes the aperture of the lens (controlling the amount of light that reaches the focal plane) by adjusting the iris of the lens.
Fill flash – A flash technique used to brighten deep shadow areas, typically outdoors on sunny days. Some digital cameras include a fill flash mode that forces the flash to fire, even in bright light.
Grayscale – A photo made up of varying tones of black and white. Grayscale is synonymous with black and white.
Highlights – The brightest parts of a photo.
Histogram – A graphic representation of the range of tones from dark to light in a photo. Some digital cameras and all SLRs include a histogram feature that enables a precise check on the exposure of the photo.
Hot shoe - A clip on the top of the camera that attaches a flash unit and provides an electrical link to synchronize the flash with the camera shutter.
Image browser/viewer– An application that enables you to view digital photos. Some browsers also allow you to rename files, convert photos from one file format to another, add text descriptions, edit photos, read EXIF info and more.
Image editor – A computer program that enables you to adjust a photo to improve its appearance. With image editing software, you can darken or lighten a photo, rotate it, adjust its contrast, crop out extraneous detail, remove red-eye and much more.
Image resolution - The number of pixels in a digital photo is commonly referred to as its resolution.
ISO – A rating of a camera sensor’s sensitivity to light. Digital cameras often include an option for adjusting the ISO setting; they will adjust it automatically depending on the lighting conditions, adjusting it upwards as the available light dims. Generally, as ISO speed climbs, image quality drops. Use a higher setting manually in dim light when you aren’t using flash.
JPEG – A standard for compressing image data developed by the Joint Photographic Experts Group. It’s a compression method that is used within a file format, such as the EXIF-JPEG format common to digital cameras. Some quality is lost in achieving JPEG’s high compression rates. Usually, if a high-quality, low-compression JPEG setting is chosen on a digital camera, the loss of quality is not detectable to the eye.
Landscape mode - holding the camera in its normal orientation to hake a horizontally oriented photograph
LCD – Liquid Crystal Display: a low-power monitor used on the rear of a digital camera to display settings or the photos themselves or use to compose photos in shooting modes.
Macro mode - a mode that allows you to get very close to objects so they appear greatly enlarged in the picture. Most compact cameras have a macro setting with an icon of a flower to designate it.
Megapixel – Equal to one million pixels.
Panning – A photography technique in which the camera follows a moving subject. Done correctly, the subject is sharp and clear, while the background is blurred, giving a sense of motion to the photo.
Pixel – Picture Element: smallest element of a digital photograph.
Portrait mode - turning the camera sideways to take a vertically oriented photograph.
Red-eye – The red glow from a subject’s eyes caused by light from a flash reflecting off the blood vessels behind the retina in the eye. The effect is most common when light levels are low, outdoors at dusk or dawn, or indoor in a dimly-lit room. Most cameras have a redeye reduction flash setting.
Sharpness – The clarity of detail in a photo.
Shutter - The device in the camera that opens and closes to let light from the scene strike the image sensor and expose the image.
Shutter speed – The camera’s shutter speed is a measurement of how long its shutter remains open as the picture is taken. The slower the shutter speed, the longer the exposure time. When the shutter speed is set to 1/125 or simply 125, this means that the shutter will be open for exactly 1/125th of one second. The shutter speed and aperture together control the amount of light reaching the sensor. Many digital cameras have a shutter priority mode that allows you to set the shutter speed to your liking while the camera automatically sets the aperture. See also aperture.
Thumbnail – A small version of a photo. Image browsers commonly display thumbnails of photos several or even dozens at a time. In Windows Pictures, you can view thumbnails of photos in Thumbnail view.
White balance - Compensates for different types of light that can create a dominant hue of color that needs to be corrected to produce more natural results. Typical settings include sunny, cloudy, tungsten, and fluorescent. Auto is normally the default setting. It can also be set manually on advanced cameras.
Zoom lens - 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