GLOSSARY GLOSSARY
equivalent exposures Images that have the
same exposure value but use a different combina-
tion of shutter speed, aperture, and ISO settings.
See also exposure and exposure value.
equivalent focal length The focal length of
lenses attached to cropped sensors needs to be
translated from the 35mm standard due to their
reduced size. The quick way to determine the
equivalent focal length of a lens when attached
to a cropped sensor camera is to multiply the
focal length by 1.5 or 1.6 depending on the
camera.
exposure The amount of light that reaches the
camera sensor. See also proper exposure.
exposure compensation A method of adjusting
the exposure so it differs from the metered reading.
exposure metering Using the light meter built
into the camera to determine the proper expo-
sure. See also metering modes.
exposure value A numerical value describing
the exposure. A value of 0 is for proper exposures,
while positive numbers describe an exposure that
is overexposed and negative numbers describe an
underexposed image. See also proper exposure.
fast A description referring to the maximum
aperture of a lens. Lenses with apertures of f/2.8
and higher are considered fast lenses. See also
slow.
fill flash A method where the flash is used to
reveal details in shadow areas that would usually
be lost.
filter A glass, plastic, or gel piece that goes in
front of the lens. Filters can be used to alter the
color and intensity of light, add special effects
like soft focus, and protect the front elements
of the lens.compression Reducing image file size when sav-
ing the image by either removing information
(lossy compression) or writing the information in a
form that can be re-created without any quality loss
(lossless compression). See also lossless and lossy.
contrast The difference between the highlights
and the shadows of a scene.
cool A descriptive term for an image or scene
that has a bluish cast.
crop To trim the edges of an image; this is usu-
ally done in postproduction.
dedicated flash A flash unit that works with the
camera either in the camera’s hot shoe or as an
external flash triggered by the camera.
depth of field (DOF) The area of acceptably
sharp focus in front of and behind the focus
point. A shallow depth of field means that the
area in acceptable focus is rather small, while a
deep depth of field means that the area in accept-
able focus is larger.
diaphragm An adjustable opening in the lens
that controls the amount of light reaching the
sensor. Opening and closing the diaphragm
changes the aperture. See also f-stop.
diffused lighting Light that has been scattered
and spread out by being bounced off a wall or
ceiling or shot through a semi-opaque material,
creating a softer, more even light. Diffused light-
ing can also take the form of sunlight shining
through the clouds.
digital noise See noise.
dSLR A digital Single Lens Reflex camera uses
a mechanical mirror to show the scene that is vis-
ible through the lens attached to the camera.
This allows you to compose the scene exactly as it
is going to be captured.