Camera Sensitivity - Iso; Flash Range And Camera Sensitivity - Minolta Dimage 7Hi Owner's Manual

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 conditions
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 settings (400, 800) will allow the photographer to
hand hold the camera in low-light conditions without the need of a flash.
Camera Notes
57
When making bulb exposures (p. ), noise can be more pronounced because of the unusual-
ly long exposure times, especially at 400 and 800 ISO. Longer bulb exposures at lower ISO
settings 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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A
DVANCED RECORDING

FLASH RANGE AND CAMERA SENSITIVITY

For correct flash exposures, the subject must be within the flash range. The flash range
can be extended by changing the camera sensitivity. When the camera sensitivity is set
to auto, the ISO is set between ISO 100 and 200. The flash range is measured from
the CCD. Because of the optical system, the flash range is not the same at the lens'
wide-angle position as it is at the telephoto position.
ISO setting Flash range (wide angle)
AUTO 0.5m ~ 3.8m / 1.6 ft. ~ 12.5 ft.
100 0.5m ~ 2.7m / 1.6 ft. ~ 8.8 ft.
200
0.5m ~ 3.8m / 1.6 ft. ~ 12.5 ft.
400 0.5m ~ 5.4m / 1.6 ft. ~ 17.6 ft.
800
0.5m ~ 7.6m / 1.6 ft. ~ 25 ft.
SHUTTER-SPEED RANGE
The slowest shutter speed that can be selected may be less than 15 seconds. This
varies with the exposure mode, focal length, camera sensitivity setting, and aperture in
use. Exposures are limited to the camera's exposure control range, see the chart
below. If the required shutter speed cannot be set, increase the aperture or use the
bulb setting in the manual exposure mode (p. 57).
Exposure mode
Program / Aperture priority
Shutter priority / Manual
Flash range (telephoto)
0.5m ~ 3.0m / 1.6 ft. ~ 9.8 ft.
0.5m ~ 2.1m / 1.6 ft. ~ 6.9 ft.
0.5m ~ 3.0m / 1.6 ft. ~ 9.8 ft.
0.5m ~ 4.2m / 1.6 ft. ~ 13.8 ft.
0.5m ~ 6.0m / 1.6 ft. ~ 19.6 ft.
Wide-angle
Telephoto
–1 ~ 18 Ev –0.4 ~ 18.7 Ev
–1 ~ 17 Ev –0.4 ~ 17.7 Ev
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