For sophisticated wireless flash setups, there's nothing like the new Speedlite Transmitter ST-E3-RT*. Facilitating radio controlled, two-way wireless transmission up to 98.4 feet, among up to five groups or fifteen individual Speedlites, the ST-E3-RT represents the next generation in wireless flash systems. With operational controls similar to the new Speedlite 600EX-RT, including diverse flash metering options, and a number of flash modes, the Speedlite Transmitter ST-E3-RT makes complex lighting setups simple. With a compact design and highly reliable construction, combined with a clearly laid-out information panel and buttons with back lighting and more, the Speedlite Transmitter ST-E3-RT is an indispensible tool for advanced, professional flash photography.
*Because it does not have an optical transmission function, the Speedlite Transmitter ST-E3-RT is not compatible with earlier Speedlite models such as 580EX II.
Type Radio transmissions wireless Speedlite transmitter
Compatible Cameras Type A EOS cameras (E-TTL II/E-TTL autoflash)
Sync Speed High-Speed Sync provided (EOS-1D X and EOS 5D Mark III only)
Flash Exposure Confirmation Flash exposure confirmation lamp lights in green
* If it does not light, shooting is not performed with the standard exposure
AF Assist Beam N/A
Transmission System Radio Transmission
Transmission Range Approx. 98.4 ft. (30m)
Flash Ratio Control 1:8 - 1:1 - 8:1, power 1/2-stop increments
Flash Coverage Transmission Angle: 360° all around
Slave Operation Confirmation Green Light
Lit: Radio Transmissions Okay
Lit: Not Connected
Blinking: Transmission Error/ Too many units (Master units + slave units = more than 16 units)
Lit: Sub-master transmission
Blinking: Receiving remote release shooting, linked shooting signal
Slave Unit SE Mode Cancellation The test flash button can be pressed to test if the slave units fire or cancel the auto power off status.
Power Source AA/LRG Alkaline Batteries x2 (Ni-MH and Lithium batteries can also be used)
Battery Life: Approx. 10 hours continuously *When using AA/LR6 alkaline batteries used (At a room temperature +23°C/73°F).
SE Mode Power off after 5 min. of idle operation
Dimensions 2.65 (W) x 2.42 (H) x 3.05 (D) in. / 67.4 (W) x 61.5 (H) x 77.4 (D) mm
Weight 3.9 oz. / 110g (excluding battery)