Well what do you know?
Obviously not enough about my camera in my case!!
Press and hold the shutter button halfway down.
The image freezes momentarily, but is not yet recorded. While the AE/AF lock indicator is flashing, the camera automatically adjusts the exposure and focus of the captured image. When the camera finishes the automatic adjustments, the AE/AF lock indicator stops flashing, then lights up and the camera is ready for recording.
If you release the shutter button, the recording will be cancelled.
I imagine this is the same on the P5 as they seem to be pretty much the same technology. I look forward to playing some more when I get it back.
Jonathan