buffer The digital camera’s internal memory where an image is stored immediately after
it is taken until it can be written to the camera’s non-volatile (semi-permanent) mem-
ory card.
burst mode The digital camera’s equivalent of the film camera’s motor drive, used to
take multiple shots within a short period of time, each stored in a memory buffer tem-
porarily before writing them to the media.
calibration A process used to correct for the differences in the output of a printer or
monitor when compared to the original image. Once you’ve calibrated your scanner,
monitor, and/or your image editor, the images you see on the screen more closely rep-
resent what you’ll get from your printer, even though calibration is never perfect.
Camera Raw A plug-in included with Photoshop and Photoshop Elements that can
manipulate the unprocessed images captured by digital cameras, such as the Nikon
D7000’s NEF files. The latest versions of this module can also work with JPEG and
TIFF images.
camera shake Movement of the camera, aggravated by slower shutter speeds, which
produces a blurred image.
Center-weighted meter A light-measuring device that emphasizes the area in the mid-
dle of the frame when calculating the correct exposure for an image. See also Matrix
metering and Spot meter.
channel In an electronic flash, a channel is a protocol used to communicate between
a master flash unit and the remote units slaved to that main flash. The ability to change
channels allows several master flash units to operate in the same environment without
interfering with each other.
chromatic aberration An image defect, often seen as green or purple fringing around
the edges of an object, caused by a lens failing to focus all colors of a light source at the
same point. See also fringing.
circle of confusion A term applied to the fuzzy discs produced when a point of light
is out of focus. The circle of confusion is not a fixed size. The viewing distance and
amount of enlargement of the image determine whether we see a particular spot on the
image as a point or as a disc. See also bokeh.
close-up lens A lens add-on that allows you to take pictures at a distance that is less
than the closest-focusing distance of the lens alone.
color correction Changing the relative amounts of color in an image to produce a
desired effect, typically a more accurate representation of those colors. Color correction
can fix faulty color balance in the original image, or compensate for the deficiencies of
the inks used to reproduce the image.
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