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.

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.

Specifications

  • 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)

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

Low Power2

Yes, 1/8192 (EL-1) / 1/1024 (EL-5)
No

FE memory

Yes
Yes

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

-
-

Wireless second curtain sync

No
No

Low Power2

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

FE memory

Yes
Yes

  1. Compatible cameras may need the latest firmware update.
  2. Minimum flash output of down to 1/8192 (EL-1) and 1/1024 (EL-5) possible (1/128 with high-speed sync).
Speedlite Transmitter ST-E3-RT V3

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

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  1. All data is based on Canon standard testing methods except where indicated.
  2. Subject to change without notice.
  3. Remote release from receiver and receiver function of linked shooting are not available when using SPEEDLITE TRANSMITTER ST-E3-RT (Ver.3) with cameras equipped with an N3 remote control terminal and compatible with E-TTL II/E-TTL autoflash, released in or before 2011.
  4. With compatible cameras launched from 2020, e.g. EOS-1D X Mark III, EOS R5/R6 and later, but excluding EOS 850D.