Appen
d
ix
106
Glossary
Digital zoom
: Unlike optical zoom, digital zoom does not increase the amount of visible detail. Instead, details
visible using optical zoom are simply enlarged, producing a slightly “grainy” image.
EV
(
E
xposure
V
alue): The exposure value is determined by the sensitivity of the image sensor and the amount
of light that enters the camera while the image sensor is exposed. Each time the amount of light doubles, EV
increases by one; each time the amount of light is halved, EV decreases by one. The amount of light entering the
camera can be controlled by adjusting aperture and shutter speed.
Exif Print
: A standard that allows information stored with pictures to be used for optimal color reproduction
during printing.
JPEG
(
J
oint
P
hotographic
E
xperts
G
roup): A compressed file format for color images. The higher the compression
rate, the greater the loss of information and more noticeable drop in quality when the picture is displayed.
Motion JPEG
: An AVI (
A
udio
V
ideo
I
nterleave) format that stores sound and JPEG images in a single file. Motion
JPEG files can be played in Windows Media Player (requires DirectX 8.0 or later) or QuickTime 3.0 or later.
Smear
: A phenomenon specific to CCDs which causes white streaks to appear when very bright light sources,
such as the sun or reflected sunlight, appear in the frame.
White balance
: The human brain automatically adapts to changes in the color of light, with the result that objects
that appear white under one light source still appear white when the color of the light source changes. Digital
cameras can mimic this adjustment by processing images according to the color of the light source. This
process is known as “white balance.”
Appendix
