The maximum size of the hole through which light
enters the camera.
Artifact
Unwanted distortions in an image caused by image
compression.
Aspect Ratio
The ratio between the width and height of an
image.
B
Bit
The smallest unit of computer memory.
Bitmap
A method of storing information that maps an image
pixel bit by bit.
Byte
A group of 8 bits, the basic unit of information
for the computer.
C
Chromatic Aberration
A fringing effect around the edges, which is caused
by the lens not focusing correctly.
Color Depth
The number of bits assigned to each pixel in the
image and the number of colors that can be created
from those bits.
D
Depth of Field
The distance between the nearest and farthest points
that appear in sharp focus in a photograph.
Digital Zoom
A digital magnification of the center 50% of an image.
Digital zooms increase the apparent image size by
interpolation. They do not increase the amount of
image information.
DPI
Dots per Inch. A measurement of the resolution of a
digital photo or digital camera. The higher the number,
the greater the resolution.
E
EXIF
Exchangeable Image File. This file format embeds camera
and exposure information into the graphic file created
by the camera.
Exposure
The length of time that the lens is open, allowing light
to fall on the camera's image sensor.
F
F-stop
A numerical designation indicating the size of the
aperture.
Flash Mode
The camera mode that determines how the internal flash is used
in the photo.
Focal Length
The distance from a point where an image is formed (the
focal point) to a point in or near the camera lens.
