From Cactus:
The last remaining X-TTL firmware version for Canon is NOW available!
Hong Kong, June 1, 2018 – Besides retaining the revolutionary cross-brand abilities of remote power control and wireless HSS of Canon, Fujifilm, Nikon, Olympus, Panasonic, Pentax and Sigma flashes simultaneously, the new system-specific X-TTL firmware for Canon adds TTL on-camera and wireless TTL in off-camera setup for Canon flashes.
Wireless E-TTL
The Canon system is unique where only Canon system flashes, Cactus RF60 and RF60X flash can be triggered by a Canon camera for wireless TTL.
Features at a glance
New Protocol and Upcoming Firmware Releases
Since the release of Pentax X-TTL firmware, a new wireless protocol has been adopted.3 To work seamlessly with a Cactus RF60 and RF60X, be sure to also update to the latest firmware.
This Canon version is the last leg of X-TTL firmware on the Cactus V6 II. Together with recent released X-TTL firmware for Fujifilm, Sigma and Sony, now are X-TTL firmware versions are running on the new wireless protocol. Next on the list for update is the original V6 (current firmware 2.1.001) and Multi-brand HSS firmware on the V6 II (current firmware 1.1.013) where they will be made to operate on the new protocol in the near future.
To download the latest firmware versions for each of the Cactus devices, get the latest Cactus Firmware Updater and you will be able to select the latest firmware versions.
Price and Availability
System-specific X-TTL firmware versions are FREE of charge. Download the Cactus Firmware Updater and select the corresponding system firmware to install the Canon X-TTL firmware on the Cactus V6 II.
Cactus V6 II Transceiver Retailers – B&H | Adorama | Amazon
1 With the exception of Pentax system flashes due to special timing requirements so it must be paired with a Pentax camera in order to support HSS.
2 Applies to both on and off-camera setups.
3 To understand more about the new protocol and how to update your firmware, please visit X-TTL microsite at https://www.cactus-image.com/special/X-TTL/.