Wireless Transmitter

Canon Speedlite Transmitter ST-E3-RT (Ver.3)

Fire compatible Speedlite flashguns over distances of up to 30m. Radio-frequency control provides reliable operation without direct line of sight. Additional features for the Speedlite EL-1 and EL-5 supported.

Remote flash trigger for Speedlite flashes

Sophisticated remote flash photography is made easy with the SPEEDLITE TRANSMITTER ST-E3-RT (Ver.3): fire multiple flashes at once, and control settings from a distance. Fire multiple cameras from a distance for synchronised shooting.

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Reliable off-camera flash control

Control compatible Canon Speedlite flashguns over distances up to 30m. 2.4GHz radio frequency triggering operates reliably, even when shooting outdoors and around corners – direct line of sight not required.
Multiple flash photography

Create intricate multi-flash lighting set ups, triggering up to 15 Speedlite flashes with a single camera-mounted Speedlite Transmitter SPEEDLITE TRANSMITTER ST-E3-RT (Ver.3). E-TTL II flash metering makes exposure control easy.
Remote camera control

Trigger an EOS camera³ fitted with a Speedlite Transmitter from a second unit or from a compatible Speedlite flashgun, such as the Speedlite 600EX II-RT. Up to 15 cameras can be triggered at once, for synchronised shooting.
Easy to use design

The Speedlite Transmitter SPEEDLITE TRANSMITTER ST-E3-RT (Ver.3) is sealed against dust and moisture to the same degree as professional EOS cameras and L-series lenses. It features an easy to read back-lit LCD control screen and is powered by two AA/LR6 batteries.
Wireless second curtain sync⁴

The SPEEDLITE TRANSMITTER ST-E3-RT (Ver.3) supports wireless second curtain sync for the EL-1/EL-5 when fired remotely, plus down to 1/8192 nuance lighting and flash exposure (FE) memory.

Radio frequency remote flash trigger
Fire selected Speedlites from 30m away
Part of the E-TTL II flash system
Controls up to 15 flashguns
Remote camera triggering*
(*See specifications)
Weather sealed against dust and moisture
Second curtain sync, down to 1/8192 power and FE memory for EL-1 and EL-5*
(*See specifications)

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Additional functions supported by SPEEDLITE TRANSMITTER ST-E3-RT (VER.3) / ST-E3-RT(Ver.2) vs ST-E3-RT

Speedlite EL-1, EL-5

Speedlite 600EX-RT, 600EX II-RT, 430EX III-RT

Cameras released from 2020¹ (e.g., EOS-1D X MkIII, EOS R5/R6 and later, but excluding EOS 850D)

Wireless second curtain sync

Yes

Low Power²

Yes, 1/8192 (EL-1) / 1/1024 (EL-5)

FE memory

Yes

Other cameras from before 2020¹ (e.g., EOS-1D X Mark II)

Wireless second curtain sync

Low Power²

Yes, 1/8192 (EL-1) / 1/1024 (EL-5) (no camera UI)

FE memory

Yes

Specifications for Speedlite EL-1

Specifications for Speedlite EL-5

Specifications for 600EX II-RT

Specifications for 600EX-RT

Specifications for 430EX III-RT

Compatible cameras may need the latest firmware update.
Minimum flash output of down to 1/8192 (EL-1) and 1/1024 (EL-5) possible (1/128 with high-speed sync).

What's in the box

Everything you need to capture amazing remote flash images, just add flashes and cameras.

SPEEDLITE TRANSMITTER ST-E3-RT (Ver.3)
Soft Case