The PocketWizard FlexTT5 Transceiver Radio Slave is part of an ultra-versatile radio slave system, and is dedicated specifically to the Canon E-TTL II flash control system. It simply slides directly into the camera's hot shoe, and there are no special settings to make or modes to call up. Use the camera, on-camera flash, or flash commander controls for flash compensation, zone and ratio control. It supports single or multiple dedicated flash units.
The FlexTT5 is the ideal addition to most Canon E-TTL II flash system. Since this system works on digital radio technology, it can support E-TTL operation around corners, out-of-sight, or in bright sunlight.
The FlexTT5 is a "Transceiver", meaning it can be used either as a transmitter when placed into the camera's hot shoe in combination with another FlexTT5 unit on the flash end, or as a receiver with a MiniTT1 transmitter-only unit placed on the camera's hot shoe.
While the FlexTT5 works ideally with many older Canon flashes, the 580EX, 580EX II, and 430EX emit strong RF noise across the PocketWizard's frequency range, and this significantly reduces out-of-box range performance of the FlexTT5 Transceiver. In PocketWizard's research, the interference from the flash varies wildly from sample to sample; they can only guarantee that the flash will work to ~30' (~10m) in all conditions, although they do have many suggestions for increasing this considerably.
Requires 2 AA Batteries that are not included in the rental
Quick Guide can be found HERE