128
S
A
Minimum Shutter Speed
Auto shutter-speed selection can be fine-tuned by highlighting
Auto
and pressing
2
: for example, values faster than those usually selected
automatically can be used with telephoto lenses to reduce blur. Note,
however, that
Auto
functions only with CPU lenses; if a non-CPU lens is
used without lens data, minimum shutter speed is fixed at
1
/
30
s.
Shutter speeds may drop below the selected minimum if optimum
exposure can not be achieved at the ISO sensitivity chosen for
Maximum sensitivity
.
A
Turning Auto ISO Sensitivity Control On or Off
You can turn auto ISO sensitivity control on or
off by pressing the
S
(
Q
) button and
rotating the sub-command dial. The top
control panel and viewfinder display
ISO-AUTO
icons when auto ISO sensitivity control is on
and
ISO
when it is off.
A
Auto ISO Sensitivity Control
When a flash is used, minimum shutter speed will be set to the value
selected for
Minimum shutter speed
unless this value is faster than
Custom Setting e1 (
Flash sync speed
341) or slower than Custom
Setting e2 (
Flash shutter speed
,
342), in which case the value
selected for Custom Setting e2 will be used instead. Note that ISO
sensitivity may be raised automatically when auto ISO sensitivity
control is used in combination with slow sync flash modes (available
with optional flash units;
198), possibly preventing the camera from
selecting slow shutter speeds.
A
See Also
For information on choosing the reference used to set exposure when a
flash is used with auto ISO sensitivity control, see Custom Setting e4
(
Auto
M
ISO sensitivity control