Originally posted by BobG When I put the flash in manual mode, there is no pre-flash visible in the viewfinder.
BobG
That is because the flash in manual mode is functioning independantly of the cameras meter, same for A mode on a 540 or 360.
The one big issue with the Pre-flash, both with Pentax's P-TTL and Nikon's i-TTL is that there are people out there whom are quick enough to react and close their eyes from the Pre flash, so they get the stoned have closed look when the shutter opens and the main goes off. I find that from the second shot onwards of my self with any camera with a Pre-flash my eyes are closed.
The work around is to use the 2s MLU to make sure the Pre-flash goes off before the the mirro goes off and then 2 seconds later the shutter opens and the main goes off. that give people time to blink and then recompose them self, just make sure you tell them to hold their pose till after the second flash