Originally posted by simico It does have servo mode.
I stand corrected, I had not done a firmware update on my 48-AF and was not aware they had added this feature (it did not have it prior to the 3.0 firmware update), thanks to you and @Timd for pointing this out.
Originally posted by Timd I am not sure that the Metz has a dumb optical slave. They talk about using the Pentax wireless mode (while Metz are good flashes, their interface and manuals are as bad as I have ever seen). Also, I am not sure you can switch off the pre-flash on the pop-up on any Pentax dSLR. Hence I still believe that it is triggered by the Pentax wireless system, so it is immune from being triggered by another camera. Just my thoughts - still need to confirm.
The servo mode in Metz flashes is indeed just a dumb slave mode set to ignore preflash, you can test this out by grabbing any other flash, setting it to the lowest power and firing off 2 flashes in quick succesion, the metz in servo mode will fire along with the second flash (I tried this with a Vivitar HV285), which means it will sync with any other camera or flash system that uses pre-flash for metering, it works very well with the onboard set to regular flash (more proof that the Metz in servo mode does not use or require Pentax's wireless P-TTL specification).
I was able to get the onboard flash to sync with the Metz in servo mode using the onboard as controller which I thought was pretty cool, but since I normally use radio triggers with the flashes on manual control it seems pretty moot to want to use optical sync with manual flash control (seeing as how I get better range and reliabilty using radio).