Nikon D100 User Manual
Page 93
Taking Photographs—Exposur
e
Controlling How the Camera Sets Exposure
81
A: Aperture-Priority Auto
In aperture-priority auto, you choose the aperture while the camera auto-
matically selects the shutter speed that will produce the optimal exposure.
Small apertures (high f/-numbers) increase depth of field, bringing both the
main subject and background into focus. Large apertures (low f/-numbers)
soften background details and let more light into the camera, increasing the
range of the flash and making photographs less susceptible to blurring. Ap-
erture-priority auto is only available with CPU lenses.
To take photographs in aperture-priority auto:
1
Rotate the function dial to A.
2
Rotate the sub-command dial to choose the
desired aperture. The minimum and maximum
values for aperture are determined by the lens
currently in use.
3
Frame a photograph and shoot.
Exposure Warning
If the camera is unable to produce the correct exposure at the selected aperture, the
electronic analog exposure display (
83) in the viewfinder will show the amount of
under- or over-exposure and one of the following indicators will be displayed in the
control panel and viewfinder shutter-speed displays:
Indicator
Description
Subject too bright. Choose smaller aperture (larger f/-number), lower
sensitivity (ISO equivalency), or use Neutral Density (ND) filter.
Subject too dark. Choose larger aperture (smaller f/-number), raise sen-
sitivity (ISO equivalency), or use flash (
98).