When I sold my Canon 5D Mark III and 7D Mark II cameras and bought into Sonys A7 camera system one of the deciding factors was the Sony cameras ability to use Canon lenses via third-party adapters. As someone who has a long-standing love affair with Canons L-series glass, I was loathe to give them up. A have also been a fan of Canons underrated 600 EX-RT Speedlites and I am happy to report that they work wonderfully with my Sony A7R Mark II thanks to the Yongnuo YN-E3-RT commander module.
When I invested in the 600 EX-RT system a few years ago I picked up three of the speedlites and Canons whiz-bang cool ST-E3-RT transmitter. On my Canon cameras, the ST-E3-RT allowed for radio TTL remote control, which proved to be much more dependable than the previous line-of-sight remote flash solutions. When I picked up a Fuji X-T1, I discovered the Canon transmitter didn’t fire the speedlites when on the Fuji.
A quick Google search identified a solution: Yongnuos ST-E3-RT clone, the not so cleverly named YN-E3-RT. For considerably less money than the Canon, the Yongnuo clocks in at about $75 on Amazon. I picked one up and was pleased to see it fire the 600 EX-RTs, albeit in Manual mode only.
I tend to use my flashes in manual mode most of the time anyway, so the Yongnuo YN-E3-RT is just peachy. Compared side-by-side with the Canon unit, the Yongnuo seems identical. I am not privy to the manufacturing situation for these units, but it would not surprise me one bit to learn that the Yongnuo and Canon units pass down the same assembly line. I have not used any other Yongnuo products, but I have read that their flash units also feel and work just like the models that inspired them.
Sony Passes Notes to Canon
On my Sony A7R Mark II, the Yongnuo works perfectly to control all three of my Canon 600 EX-RTs. I have had successful flash pops at distances over 100 feet and through walls. The YN-E3-RT mounts in the A7R Mark IIs hot shot without resistance, and when powered up and paired with the speedlites, the unit can be used to change each flashs power setting. Unlike the Canon ST-E3-RT on a Canon camera, the Yongnuo requires that you transmit each setting change to the speedlites by pushing the test button. The transmitter allows for all of the channel options and special functions that the Canon ST-E3-RT supports. Each speedlite can be controlled independently or as a homogenous group.
For those of us who have moved over to Sonys A7 cameras, being able to retain much of our Canon kit is a financial and functional relief. If you are building a speedlite kit for your Sony A7-series camera from scratch it wouldn’t make much sense to invest in the Canon 600 EX-RT speedlites and the Yongnuo YN-E3-RT, as there are less expensive options out there, including the TTL-capable Nissin Di700A and Air 1 combo. For me the hybrid Canon/Yongnuo solution is money saved and problems solved.