Pentax KX KX Manual - Page 24

ACTIVATING EXPOSURE METER SHUTTER BUTTON LOCK The exposure meter of the KX is switched on by moving the rapid-wind lever from its closed position to a slightly open position, which is called the pre-advance angle. With the rapid-wind lever at the pre-advance angle, as soon as the shutter release button is depressed slightly, the black needle in the viewfinder will move according to the amount of light coming in through the lens. The exposure meter will remain switched on until the rapid-wind lever has been returned to its fully-closed position. The shutter button lock lever is for your convenience while you are making a particularly long exposure using the B shutter speed setting. After depressing the shutter button, turn the lock lever (which is on the collar at the base of the shutter button) so that the letter "L" is visible. When the exposure time is up, move the lock lever back to its original position. This automatically releases the shutter button. Use of the shutter button lock lever also saves your battery as the exposure meter is switched off as soon as this lever is locked-in. 1000 c3CP 'Ne ti Sl O6, 22.