Pentax ist ist DL Operating Manual page 142

140
About the L Button
The aperture and shutter speed are automatically adjusted to the
appropriate exposure at that moment if the L button is pressed
in a (Manual) mode.
You can choose from the following three adjustment methods in [AE-
L bttn on M expsr] in the [A Custom] menu.
1 Program Line The aperture and shutter speed are adjusted automatically.
2 Tv Shift
3 Av Shift
Shutter speed is adjusted to appropriate exposure according to lens
aperture when lens aperture is not set to s position.
1 Notes on [Using Aperture Ring] (p.180)
5
Using the p (Bulb) Mode
This mode is useful for the long exposures required for shooting night
scenes and fireworks.
1
Set the mode dial to p.
• Turn the e-dial to adjust the aperture value.
• Set the aperture value in increments of 1/2EV or 1/3EV. Set in [Expsr Setting
Steps] in the [A Custom] menu. (p.142)
• Use a sturdy tripod and the cable switch CS-205 (optional) to prevent camera
shake when using p (bulb) mode. Connect the cable switch to the cable
switch terminal (p.15).
• Bulb shooting is available when using the remote control shooting mode
(p.59). The shutter remains open as long as the optional remote control's
shutter release button is held down.
• Noise reduction is a process to reduce noise (image roughness or
unevenness) caused by low shutter speed. Set in [Noise Reduction] in the
[A Custom] menu. (p.100)
• When in p (Bulb) mode, the sensitivity is equivalent to ISO 200 when
sensitivity is set to [AUTO].
The aperture is locked and the shutter speed is adjusted
automatically.
The shutter speed is locked and the aperture is adjusted
automatically.