User manual POCKETWIZARD PRE-TRIGGER CABLES

[. . . ] Plug the mini-phone connector into a PocketWizard Receiver, Time Machine, WaveSensor, or other triggering device. [. . . ] Inconsistent Lag Time is due to the electronics inside the camera which take varying times to perform metering and especially auto-focus functions. PreReleasing keeps the camera "awake" all the time which is the same as continually holding the camera's shutter release button down halfway. Consistency is even further increased by setting as many of the camera's functions as possible to MANUAL modes. A drawback to this mode of operation (as stated above) is that the battery life of the camera is extremely diminished. This is due to the power required to keep the camera "awake. " If you simply trigger a camera via the motor drive port without "waking it up" (the cable's switch is set to Normal) it will perform the functions it is programmed to do after a brief delay. Some auto-focus cameras can be programmed to fire only when they are in sharp focus which, upon "waking up" the camera, can take a widely varying time due to the mechanics of moving the lens. Experimentation with your camera's autonomic functions is the best way to determine an operation mode suitable for your situation. Why a Pre-Release cable?Some photographic events require a degree of precision in timing that a varying Lag Time makes impossible to capture. [. . . ] The addition of a Pre-Release cable to the WaveSensor and Time Machine kits makes for even finer control over the capture of a photographic event. [. . . ]