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MISCELLANEOUS
Glossary
CPU
Central Processing Unit. The electronic component that controls an electronic product’s
functions.
AF Nikkor (including G- and D-type AF Nikkor) and AI-P-Nikkor lenses have built-in
CPUs.
EV
Exposure Value: A number representing the available combinations of shutter speeds
and apertures that give the same exposure effect under conditions of similar scene
brightness and ISO.
At ISO 100, the combination of a one-second shutter speed and an aperture of f/1.4 is
defined as EV1.
The camera can be used only within the EV range of the exposure meter. For example,
with the F55/F55D, the exposure metering range is from EV1 to EV20 at ISO 100 with an
f/1.4 lens.
Exposure bracketing
Shooting the same subject a number of times at a range of different exposures to attain
proper exposure. Three shots with metered EV, under EV, and over EV exposure are
performed in that order with the F55/F55D.
Automatic exposure bracketing is performed with varied shutter speeds and/or
apertures.
Exposure Compensation
In a situation such as when your subject is strongly backlit, exposure compensation
enables you to intentionally compensate the standard exposure value measured by the
camera to create a desired effect. Exposure compensation of –2 EV to +2 EV in 1/2
steps is available with the F55/F55D.
Flash shooting distance range
The distance range over which a flash can effectively provide light. Flash shooting
distance range is controlled by the amount of flash output available. Each automatic
Speedlight’s flash output varies from maximum duration to minimum duration. Close-up
subjects will require lower (to minimum) output, while more distant subjects will require
more light up to the maximum output.
The flash shooting distance range varies with the aperture, film speed, etc.
Flash sync speed
Shutter speed at which the entire film frame is exposed when the flash is fired in flash
shooting. The F55/F55D’s flash sync speed is 1/90 sec. or slower.
Flexible Program
Flexible Program function temporarily shifts an automatically selected shutter
speed/aperture combination while maintaining correct exposure. That is, the desired
shutter speed or aperture can be selected in Auto-Multi Program.
f-number
The f-number represents the aperture value and is calculated from lens’ focal length
divided by the effective aperture opening. The standard numbers for calibration are 1,
1.4, 2, 2.8, 4, 5.6, 8, 11, 16, 22, 32, etc.
The smallest f-number is called maximum aperture and the largest f-number is called
minimum aperture. Lenses with large maximum apertures (smaller f-numbers) are ‘fast’
lenses that allow photographers to use faster shutter speeds in dim light. Lenses with
smaller maximum apertures (larger f-numbers) allow the use of lower shutter speeds for
available light but are also lighter and smaller than faster lenses. With some zoom
lenses, aperture varies depending on the focal length setting.
Focal length
The distance from the principal point to the focal point. In 35mm-format cameras, lenses
with a focal length of approx. 50mm are called normal or standard lenses. Lenses with a
focal length less than approx. 35mm are called wideangle lenses, and lenses with a focal
length more than approx. 85mm are called telephoto lenses. Lenses which allow the user
to continuously vary the focal length without changing focus are called zoom lenses.
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