Sensitivity (iso equivalency), Indicator – Nikon 990 User Manual

Page 48

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Advanced Photo

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y:

Sensitivity (ISO Equivalency)

48

Sensitivity (ISO Equivalency)

In A-REC mode, automatic gain control is used to produce

sensitivity equivalent to ISO 100 film. In M-REC mode, you can

choose increased values for sensitivity, or allow the camera to

set sensitivity in response to lighting conditions. Increasing

sensitivity reduces the time needed to make an exposure, al-

lowing increased shutter speed. This can be used to reduce

blurring caused by camera motion when lighting is poor, or to

“freeze” moving objects. Sensitivity is adjusted as shown be-

low:

Press while turning

command dial to cycle

through sensitivity
settings as follows:

100

200

400

AUTO

Sensitivity setting is
displayed in LCD
monitor, and in
control panel while
command dial is
rotated. After
command dial is
released, ISO icon in
control panel
indicates that
sensitivity adjustment
is in effect.

P 1/60

1/60 F2.7

2.7

AUT

UTO

NORMAL

NORMAL

[

10

10

]

The following settings are available:

Setting

Description

100

Approximately equivalent to ISO 100 (default)

200

400

Approximately equivalent to ISO 400

A slight amount of noise may appear in photographs taken at settings
other than 100.

In a film camera, sensitivity is a characteristic of the film, not the camera.
Sensitivity determines the amount of light needed to produce a given de-
gree of exposure. The more sensitive the film, the less light needed to
make an exposure, allowing higher shutter speeds. Higher sensitivity is
achieved by altering the chemical composition of the film, causing a ran-
dom pattern, called “grain,” to appear in the final photograph. In a digital
camera, sensitivity has a similar effect: higher sensitivities allow higher shut-
ter speeds, at the expense of “noise” (the digital equivalent of film “grain”)
appearing in the final image.

Changes to sensitivity have no effect in A-REC mode. Turning

the mode dial to A-REC returns sensitivity to the default value;

the M-REC setting is restored when the mode dial is set to

M-REC once again.

Approximately equivalent to ISO 200

AUTO

Equivalent to 100 under normal conditions;

when lighting is poor, however, camera will

automatically raise sensitivity to compensate.

ISO icon appears in control panel and LCD

monitor only when sensitivity is raised above 100.

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