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one method makes the other’s setting or settings unavailable, but they still
change based on adjustments you make to the available method. For example,
when Exposure Value is active, adjusting its value also changes the
Photographic Exposure > Shutter Speed setting.
Preset Choose from the available options based on setting and lighting
conditions. The presets affect all of the remaining settings in this group.
Exposure Value (EV) Choose this option to specify a single Exposure Value
setting that corresponds to a combination of the three Photographic Exposure
values (see following). Each increment or decrement in the EV value
corresponds to halving or doubling, respectively, the effective exposure, as
expressed in the resultant change in the Shutter Speed value. Thus, higher
values yield darker images, and lower values yield brighter images.
For example, as shown above, the combination of a shutter speed of 1/125 of
a second, f/16, and ISO 100 results in an EV of 15. The same EV results from
halving the shutter speed to 1/250 second and doubling the aperture size to
f/11.
Photographic Exposure Lets you set the exposure using standard
camera-oriented controls. These controls affect exposure only: Shutter Speed
has no effect on motion blur; Aperture doesn’t influence depth of field; and
Film Speed has no effect on graininess.
■ Shutter Speed The duration, in fractions of a second, that the “shutter”
is open. The higher this value, the greater the exposure.
■ Aperture The size of the opening of the “camera iris,” expressed as a
ratio. The higher this value, the lower the exposure.
■ Film Speed (ISO) The sensitivity of the “camera film,” expressed as an
index. The higher this value, the greater the exposure.
Image Control group
Use these controls to adjust the relative brightness or highlights, midtones,
and shadows in the rendered image. The combination of these three settings
is depicted in the graph on the right side of the rollout. Additional controls
available here let you adjust color saturation, whitepoint, and vignetting.
6546 | Chapter 19 Effects and Environments