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CAMERA SENSITIVITY – ISO
Five settings can be selected for camera sensitivity: Auto, 100, 200, 400, and
800; the numerical values are based on an ISO equivalent. ISO is the standard
used to indicate film sensitivity: the higher the number, the more sensitive the
film. See setting the function dial section on page 48 to change the ISO setting.
The auto setting automatically adjusts the camera sensitivity to the light condi-
tions between ISO 100 and 200. When any other setting than auto is used,
"ISO" will appear on the data panel, and "ISO" and the set value will be displayed on the monitors.
Photographers can select a specific sensitivity setting. Like grain in silver-halide film that increases
with speed, noise increases with sensitivity in digital imaging; an ISO setting of 100 will have the
least noise and 800 will have the most noise. A change in ISO also affects the flash range; the higher
the ISO, the greater the range.
As the ISO value doubles, the camera sensitivity doubles; changing the ISO between 100 and 200,
200 and 400, or 400 and 800 changes the camera sensitivity by one stop or 1 Ev (p. 79). A change
between 100 and 800 changes the camera sensitivity by a factor of 8 or three stops. High ISO set-
tings (400, 800) will allow the photographer to hand hold the camera in low-light conditions without
the need of a flash.
Camera Notes
When making bulb exposures (p. 57), noise can be more pronounced because of the unusually
long exposure times, especially at 400 and 800 ISO. Longer bulb exposures at lower ISO set-
tings will be less affected by noise than the equivalent exposure at a high ISO. For example, a
fifteen second exposure at ISO 200 will have less noise than a four second exposure at ISO
800. With long exposures at high ISO settings, noise from interference may be noticeable.
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DVANCED RECORDING
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