Pentax K-x Operating Manual page 105

Using the Bulb Shooting
This setting is useful when shooting night scenes and fireworks which
require the long exposures.
1
Set the mode dial to a.
2
Turn the e-dial and set the shutter
speed to h.
h appears after the slowest shutter
speed (30 sec.).
3
Press the shutter release button.
The shutter remains open as long as the shutter release button is kept
pressed.
EV Compensation, Continuous Shooting and Exposure Bracketing are not
available in Bulb shooting.
M
AF.A
Bulb
F
200
ISO
AWB
-3 2 1 1 2 +3
12
JPEG
M
103
4
5.6
ISO
[ ]
37