My St-e3-rt transmitter triggers my 600ex-rt flashes, but not my Mecablitz 58 AF-2 flash, is it possible?

Graham Hobbs, Peterborough

Brian Says… The ST-E3-RT communicates with the Speedlite 600EX-RT using radio wireless. Radio has the advantage that it doesn’t need line of sight between the flash and transmitter, or care how bright the ambient light is. However, your Mecablitz 58 AF-2 flash doesn’t have a radio receiver built in.

This leaves a couple of options, you can stop using the ST-E3-RT to control the other flashes, and use one of the Speedlite 600EX-RT flashes as a master using optical wireless. Optical wireless is less reliable in bright light and over longer distances, and is much less reliable if the Speedlites are fitted inside a softbox.

Another possibility is to trigger your Mecablitz with an additional radio receiver. I have used Yongnuo YNE3-RX and Phottix Laso receivers to trigger Speedlite 580EX II flashes with the ST-E3-RT transmitter. However, due to the age of your Mecablitz flash I suspect that these radio receivers will not work fully with your unit and give E-TTL automatic flash. The Yongnuo receiver can just trigger the Mecablitz in manual mode, though you’ll need a cable to link the receiver and flash.

As an alternative, you might try one of the independent radio wireless compatible flashguns, such as the Yongnuo YN600EX-RT. For relatively little money these make handy additional flashes and I have successfully used them in conjunction with Canon radio wireless Speedlites and transmitters.

A Speedlite in the lampshade couldn’t be triggered optically, but radio triggering worked

Optical wireless can be unreliable in daylight, but radio wireless can trigger the flash, even in a softbox