Nikon D90 - Manual (Page 94)

74
h
ISO Sensitivity
“ISO sensitivity” is the digital equivalent of film speed. The higher the ISO sensitivity,
the less light needed to make an exposure, allowing higher shutter speeds or smaller
apertures.
ISO sensitivity can be set between values roughly equivalent to ISO 200 and ISO 3200
in steps equivalent to
1 /
3
EV. For special situations, ISO sensitivity can be lowered
below ISO 200 by about 0.3 EV ( S, equivalent to ISO 160), 0.7 EV (T, equivalent
to ISO 125), or 1.0 EV ( U, equivalent to ISO 100), or raised above ISO 3200 by about
0.3 EV ( P, equivalent to ISO 4000), 0.7 EV (Q, equivalent to ISO 5000), or 1.0 EV
( R, equivalent to ISO 6400). Auto and scene modes also offer an AUTO option (the
default setting), which allows the camera to set ISO sensitivity automatically in
response to lighting conditions.
01 is displayed in the control panel and
viewfinder when AUTO is selected.
ISO sensitivity can be selected by pressing the W (ISO) button and rotating the main
command dial until the desired setting is displayed in the control panel. ISO
sensitivity can also be adjusted from the shooting menu (pg. 165).
A AUTO
If the mode dial is rotated to P, S, A, or M after 01 is selected for ISO sensitivity in
another mode, the ISO sensitivity last selected in P, S, A, or M mode will be restored.
A HI 0.3–HI 1
Pictures taken at these settings are more likely to be subject to noise and color distortion.
A See Also
For information on enabling auto ISO sensitivity control in P, S, A, or M modes, see page 78. For
information on using the High ISO NR option in the shooting menu to reduce noise at high ISO
sensitivities, see page 165.
W (ISO) button Main command dial Control panel