bulb A shutter speed setting that keeps the
shutter open as long as the shutter release button
is held down. This allows the shutter to remain
open longer than a camera’s built-in time limit,
which is usually 30 seconds.
cable release A cable with a button on the end
that you can attach to your camera, and which
allows you to trigger the shutter release without
having to press the shutter release button on the
camera.
camera shake The small movements of the
camera that can cause blurring, especially when
the camera is being handheld. Slower shutter
speeds and long focal lengths can contribute to
this problem.
CCD Charged Coupled Device. A type of
sensor found in some digital cameras.
center-weighted metering A metering mode
on a camera’s built-in light meter. With center-
weighted metering, the entire scene is metered,
but a greater emphasis is placed on the center area.
CMOS Complementary Metal Oxide
Semiconductor. A type of image sensor found in
some dSLRs. See also dSLR.
color space A description of the range of colors
that can be displayed or recorded accurately by the
current device. See also Adobe RGB and sRGB.
color temperature A method of measuring the
color of light 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. It is also possible to put the colored
gel between the subject and the camera which
would color the whole scene being recorded by
the camera.Adobe RGB A color space created by Adobe
Systems Inc. to more closely match the output of
inkjet printing devices. See also color space and
sRGB.
ambient light The natural light in the scene,
also referred to as available light.
angle of view The amount of the scene in front
of the camera that a specific lens sees.
aperture The variable size lens opening in the
lens that the light passes through before reaching
the sensor in the camera. You can adjust the
aperture by changing the f-stop, which controls
the diaphragm. Aperture is expressed as an f/
number — for example, f/5.6.
aperture priority mode A mode that allows you
to set the aperture while the camera sets the shut-
ter speed, also called Av or A.
autofocus A camera mode that automatically
adjusts the focus, depending on which focus point
you select. The autofocus on most digital cameras
is engaged by pressing the shutter release button
halfway down.
backlighting A method of lighting where the
main light is placed behind the subject. See also
silhouette.
bounce light Light that is bounced off a surface
before hitting the subject to create a more flatter-
ing light source. This is used mainly with a dedi-
cated flash unit that can be aimed at a wall or
ceiling.
bracket A method in which multiple exposures
of the same scene are taken, some below and
some above the recommended exposure value.
buffer The camera’s built-in memory that is
used as temporary storage before the image data is
written to the memory card.