Canon EOS 7 - Manual (Page 90)

Basic Photography Terms
Exposure
Exposure occurs when the film is exposed to light. Correct exposure is
obtained when the film is exposed to a proper amount of light in
accordance with the film’s sensitivity to light. The correct exposure is
adjusted with the camera’s shutter speed and aperture.
Shutter speed
The shutter speed is the length of time the camera’s shutter opens to
expose the film to the light coming through the lens. The shutter speed is
displayed on the camera's LCD panel and in the viewfinder. It ranges from
30 sec. to 1/4000 sec. and bulb.
Reference
Aperture
The aperture setting (f-number) indicates
the size of the aperture opening in the
lens. It is used to adjust the amount of
light striking the film. The aperture setting
is displayed on the camera’s LCD panel
and in the viewfinder. It can range
anywhere from 1.0 to 91, depending on
the lens attached to the camera.
ISO film speed
The ISO film speed indicates the film’s sensitivity to light. The higher the
film speed, the more sensitive the film is. Therefore, ISO 400 and higher-
speed films are suited for low-light conditions. The ISO film speed is set in
accordance with standards set by the International Standardization
Organization (ISO).
A film speed from 6 to 6400 can be set with the camera. The film speed is
displayed on the LCD panel and in the viewfinder.
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