Adobe RGB
A color space created by Adobe to more closely match the output of inkjet printing devices. Also see color space and sRGB.

AE lock
Pressing the camera’s AE lock button will lock the present exposure and allow you to recompose the view without changing the exposure.

AF (auto focus) lock
The focus can be locked by either pressing the Shutter button halfway down or by setting the AF/MF button to act as a AF lock button. When the focus is locked, the camera can be moved but the focus will not. The focus stays locked until the shutter is released or the Shutter button is released. This allows the scene to be recomposed without changing the focus.

ambient light
The natural light in the scene, also referred to as available light.

angle of view
The total of the scene in front of the camera that a given lens will see.

aperture
The lens opening through which the light passes before reaching the sensor in the camera. The aperture may be adjusted by controlling the diaphragm by changing the f-stop. This is expressed as f/number—for example, f/5.6.

Aperture Priority mode
In this mode the photographer sets the aperture and the camera sets the shutter speed.

artificial light
Any light that the photographer introduces into a scene.

aspect ratio
The proportions of the image captured by the camera, calculated by dividing the width of the image by the image height.

Auto adjustment mode
In this mode the camera will set the aperture, shutter speed, and ISO to achieve the correct exposure.

auto focus
The camera automatically adjusts the focus depending on which focus sensor is selected.

auto focus illuminator
A built-in red light which illuminates the scene, helping the camera achieve focus when there isn’t enough ambient light present.

Backlighting
A method of lighting where the main light is placed behind the subject. Also see silhouette.

barrel distortion
An effect which causes straight lines to bow outward, in particular at the outer edges of the frame. This effect is more visible when using wide-angle lenses.

bounce light
Light which is bounced off a surface before hitting the subject to create a more flattering light source. Used mostly with a dedicated flash unit which can be aimed at a ceiling or wall.

bracketing
A method in which multiple exposures are taken, some below and some above the recommended exposure.

buffer
The camera’s built-in memory used as a temporary storage before the image data is written to the memory card.

camera shake
The small movements of the camera which might cause blurring, particularly when the camera is being hand-held. Slower shutter speeds and long focal lengths may add to the problem.

Center-weighted metering
The entire scene is metered, but a greater emphasis is placed on the center area.

color cast
An overall look or predominant color affecting the whole image. Color casts are often brought about by a wrongly set white balance. Also see cool and warm.

color space
A description of the range of colors which can be displayed accurately by the current device. See also Adobe RGB and sRGB.

color temperature
A description of color using the Kelvin scale. See also Kelvin.

colored gel filters
Colored light modifiers that when placed between the light source and the subject change the color of the light hitting the subject.

compression
Reducing image file size by either removing information (lossy compression) or writing the information in a way which can be re-created without any quality loss (lossless compression).

Continuous Auto Focus mode
A mode in which the camera continues to refocus while the Shutter button is held halfway down. This is the best Focus mode for moving subjects.

contrast
The difference between the highlights and the shadows of a scene.

cool
A descriptive term for an image or scene having a bluish cast.

crop
To cut off or trim one or more of an image’s edges. When a camera is set to the 16:9 aspect ratio, the image is being cropped by removing data from the top and bottom of the scene.

dedicated flash
A flash unit that works with a given digital camera.

depth of field (DOF)
The area of acceptably sharp focus in front of and behind the focus point.

diaphragm
A customizable opening in the lens which controls the amount of light reaching the sensor. Opening and closing the diaphragm changes the aperture.

diffused lighting
Light which has been scattered and spread out by being bounced off a wall or ceiling or shot through a translucent material, creating a softer, more even light. Diffused lighting may also be sunlight shining through the clouds.

digital noise
See noise.

diopter
A unit of measurement used in the making of corrective lenses.

exposure
The amount of light that reaches the sensor.

exposure compensation
A method of adjusting the exposure so that it differs with the metered reading.

exposure metering
Using the light meter built into the camera to determine the proper exposure. See also Metering modes.

fill flash
A method in which the flash is used to reveal details in shadow areas which would usually be lost.

filter
A glass or plastic cover which goes in front of the lens. Filters may be used to alter the color and intensity of light, add special effects like soft focus, and protect the front elements of the lens.

flash
A device which produces a short bright burst of artificial light. The word flash can be used to describe the unit producing the light or the light itself.

flash compensation
An adjustment that changes the amount of light produced by a flash independently of the exposure settings.

flash sync
The method by which the flash is fired at the moment the camera shutter is opened.

flat
A description of an image or scene having very little difference between the light values and the dark values. An image or scene with low contrast.

focal length
The distance from the optical center of the lens when it is focused at infinity to its focal plane (sensor), described in millimeters (mm).

focal plane
The area in the camera where the light passing through the lens is focused.

Focus
The adjustment of the lens to create a distinct and clear image.

focus lock
The focus is set and does not change even if the scene is recomposed.

front lighting
A method of lighting where the main light is placed straight in front of the subject.

f-stop
A measure of the opening in the diaphragm which controls the quantity of light traveling through the lens. See also diaphragm.

high contrast
A description of an image or scene in which the shadows and highlights are at the extreme differences in density.

high key
A description of a photograph with a light tone overall.

histogram
A basic bar graph that shows the amount of pixels that fall into each of the 256 shades from pure black to pure white. The histogram view on the most advanced digital cameras also shows the values of the red, green, and blue color channels.

hot shoe
The camera mount on top of the viewfinder that accepts flash accessories. The hot shoes on the majority of digital cameras are proprietary designs and do not accept standard hot shoe accessories designed for other manufacturers.

image rotation
The ability of the camera to identify the orientation in which the photo was taken and to display the image in the correct orientation when viewing it on the LCD.

ISO International Organization for Standardization.
An international body that set standards for film speeds. The standard is also known as ISO 5800:1987 and is a mathematical representation for measuring film speeds.

ISO sensitivity
The light sensitivity of image sensors in digital cameras are rated using the standards set for film. Each doubling of the ISO makes the sensor twice as sensitive to light, meaning that in practical purposes, an ISO rating of 200 needs twice as much light as an ISO of 400.

JPEG Joint Photographic Experts Group.
The most commonly used and universally accepted method for image file compression. The JPEG is a lossy form of compression, meaning that information is lost during the compression. JPEG files have a .JPEG file extension. See also lossy.

Kelvin
Abbreviated with K, it is a unit to measure color temperature. The Kelvin scale used in photography is based on the color changes that occur when a theoretical black body is heated to different temperatures.

LCD (Liquid Crystal Display)
The type of display used on most digital cameras to preview your photos and display menus and shooting data.

light meter
A device used to measure the quantity of light in a scene. The readings from the light meter may be used to determine what settings produce a proper exposure.

lossless
A form of computer file compression that allows the original data to be reconstructed without losing any information. This is useful when it is important that no changes are made to the information. See also compression and TIFF.

lossy
A form of computer file compression which reduces the file size by removing data. The file will not be an exact match to the original file yet close enough to be of use. This form of compression suffers from generation loss. Repeatedly compressing the same file results in progressive data loss and image degradation. See also compression and JPEG.

low key
A description used to describe a photograph with a darker tone overall.

macro lens
A specialty lens that allows for extreme close-ups with a reproduction ratio of 1:1, creating life-size images.

Manual exposure mode
In this mode, the photographer determines the exposure by setting both the aperture and the shutter speed.

megapixel
A description referring to the amount of pixels that a digital camera sensor has. 1 megapixel is equal to 1 million pixels.

memory card
The removable storage device that image files are stored on. The most popular memory cards include: CompactFlash, Type I, CompactFlash, Type II, SmartMedia, MMC, MMCplus, RS-MMC, MMCmobile, MMCmicro, Memory Stick Standard, PRO, Memory Stick Duo, PRO Duo, Memory Stick Micro “M2″, SD, miniSD, microSD.

Metering modes
The method the camera uses to determine what light to use in the metering process. See also Multi-segment metering, Center-weighted metering, and Spot metering.

middle gray
A tone that represents 18-percent reflectance in visible light.

Mode dial
The large dial on the top left of the camera which is used to set the shooting mode for the camera.

Multi-segment metering
The light meter built into the digital cameras which divides the entire scene into a number of segments used to measure light.

noise
Extra unwanted pixels of random color in places where there should only be smooth color. Noise is created when the signal from the image sensor is amplified to match the ISO characteristics of film. The higher the ISO in a digital camera, the more noise is created.

noise reduction
Software or hardware used in order to reduce unwanted noise in digital images. See also noise.

normal lens
A lens which produces images in a perspective close to that of the human eye.

overexposure
Allowing more than the recommended amount of light to reach the sensor, causing the image to appear too light and with less detail in the highlights.

panning
A method involving moving the camera in the same direction and speed that the subject is moving, resulting in an image where the subject is in acceptable focus while the background is blurred.

pixel
The smallest unit that makes up a digital image.

prime lens
A lens with a single focal length.

Program Auto mode
In that mode the camera sets the shutter speed, aperture, and ISO to achieve the correct exposure in the same way as it does in the Auto adjustment mode. The photographer may adjust these settings for more control over the exposure, giving a higher level of user control over the exposure compared to the Auto adjustment mode.

RAW
A file type which stores the image data without any in-camera processing.

rear-curtain sync
The ability to fire the flash at the end of the exposure instead of at the beginning. This freezes the action at the end of the exposure.

red eye
A condition that occurs when photographing people with a flash that is too close to the lens. The light is reflected from the person’s retina, which is covered with tiny blood vessels thus the red, back toward the camera’s lens.

red-eye reduction
A flash mode which fires a short burst of light right before the photograph is taken, in the hopes of causing the subject’s pupils to contract and lessening the quantity of light which may be reflected back.

reflector
Any surface which may be used to redirect light. Specialty reflectors for photography come in different shapes, colors, and sizes and are designed to reflect light onto the subject.

resolution
The quantity of pixels counted either vertically or horizontally in a given area.

saturation
In color, it is the intensity of a specific hue.

self-timer
The ability of the camera to take an exposure after a predetermined amount of time when the Shutter button has been pressed.

sharp
A way to describe a well-focused image.

shutter
A movable cover that controls the amount of light that is allowed to reach the sensor, by opening for a specific length of time designated by the shutter speed.

Shutter button
The button used to move the shutter out of the way, so that a photograph can be taken.

shutter speed
The amount of time that the shutter is open and letting light reach the image sensor.

Shutter Speed
In this mode the photographer can set the shutter speed and the camera will set the aperture.

side lighting
A method of lighting in which the main light source is to the side of the subject.

silhouette
An image or scene in which the subject is represented by a solid black object against a lighter background. See also backlighting.

slow
A description referring to the maximum aperture of a lens. Lenses with a maximum aperture of f/8 are considered very slow. See also fast.

Spot metering
The only area that the camera uses to meter the light is a small area in the center of the scene.

sRGB
A color space created by Hewlett-Packard and Microsoft to more closely match display devices. sRGB is the standard color space used on the Internet. See also Adobe RGB and color space.

stop
A term of measurement in photography refering to any adjustment in the exposure. When stop is used to describe shutter speed, a 1-stop increase doubles the shutter speed, and a 1-stop decrease halves the shutter speed. When stop is used to describe aperture, a 1-stop increase doubles the amount of light reaching the sensor, and a 1-stop decrease halves the light reaching the sensor.

Super SteadyShot
Vibration reduction technology. The camera can shift the sensor in order to match the movement of the camera body, resulting in sharper photos when using longer shutter speeds.

telephoto effect
A photographic optical illusion occuring when using a long focal length lens where objects can appear closer together than they really are.

telephoto lens
A lens with a focal length longer than normal.

TIFF Tagged Image File Format.
A lossless file format for images. It is universally acceptable by image editing software. See also lossless.

tonal range
The shades of gray that exist between solid black and solid white.

top lighting
A method of lighting where the main light is placed above the subject.

tungsten light
A light source that produces light with a color temperature of approximately 3200K.

underexposure
Allowing less than the recommended amount of light to reach the sensor, causing the image to appear too dark and a loss of detail in the shadows.

vibration reduction
See Super SteadyShot.

warm
A descriptive term for an image or scene which has an orange or red cast.

white balance
An adjustment to the colors that the camera records to match the lighting of the scene.

wide-angle lens
A lens description which refers to lenses with shorter-than-normal focal lengths.

zoom lens
A lens that has a range of focal lengths.