Guide numbers: The number given to a flashbulb or electronic
speedlight unit to indicate its power. A guide number may be
quoted
in
meters or feet, and depends
on
the speed of the film
being used. Quoted guide numbers assume a relatively efficient
reflector surrounding the flash source,
in
an
average
-s
ized room.
ISO:
The international standard for representing film sensitivity
(speed with which
it
reacts to light). The
ISO
film speed scale
is
arithmetical, with a film speed of
IS0
200 being twice as fast
as
IS0100, and half the speed of
IS0400
film.
LED: Abbreviation of Light-Emitting Diode. Used to provide
indications inside the camera viewfinder.
Multi-sensor metering: Nikon
's
exclusive metering system.
Drawing
on
its rich experience of auto exposure technology,
Nikon has incorporated a unique multi-sensor light meter into
the N4004s. The multi sensor provides additional information
to
Decision Master System by dividing the scene into three
areas to instantly and automatically gauge brightness and
contrast. This enables the N4004s
to
handle all kinds
of
lighting situations, including high-contrast or backlit scenes,
or scenes with a bright sun
in
the
picture
.
TTL: Abbreviation of Through-The-Lens. Most
SLR
cameras
have built-in meters which measure light after
it
has passed
through the lens, a feature that enables exposure readings to
be taken from the actual image about to
be
re
corded
on
film,
whatever the lens' angle of view and regardless of whether
a filter is used.
TTL auto flash mode:
In
this mode, the camera
's
light sensor
measures flash light,
as
reflected by the subject
on
the film, and
shuts off the flash when measurement indicates correct expo-
sure. Because the sensor that controls the flash receives light
through the lens, this mode can
be
used for bounce photography,
fill-in flash, multiple flash photography, etc. The major advantage
of this mode
is
that you can use a wide range of aperture
setti
ng
s that will give correct exposure.
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