Originally posted by novsky Thanks ClassA, u said that a V6 can pick up optical signal from my on-camera Pentax 540 (Metz can't be master in HSS) and transmit it to another V6.
Just to clarify that this optical->radio conversion works for triggering (including HSS) only.
The V6 will not fully preserve all optical signals and convert them to radio waves. The Akoatec AK-TTL do that but they need some bulky contraptions to accomplish this.
The Akoatec AK-TTL make more sense for the flash systems of Canon and Nikon that actually have some support for controlling multiple flash setups. When considering P-TTL, however, I feel that the V6 covers it very well with its ability to remote control the power of flashes and trigger them.