The Speedlite Transmitter ST-E3-RT (Ver.2) provides some much anticipated upgrades from professionals to make it an even more appealing resource for flash photography when used with the Speedlite EL-1. This updated version allows for wireless rear curtain synchronization to capture ambient light trails and convey a sense of speed for moving subjects. The expansive minimum output range (down to 1/8192 power) gives you increased opportunity for creativity over the flash output from brightest to dimmest. And you now have FE Memory as part of the radio transmitter, so you can lock-in an E-TTL flash exposure level, even in complex multi-flash set-ups, and continue to use it for the same scene or subject. These improvements combine with the previous benefits of its predecessor including radio controlled, two-way wireless transmission up to 98.4 ft., among up to five groups or fifteen individual Speedlites, a dot matrix LCD with backlighting, intuitive controls and more.

Updated to include Wireless Rear Curtain Synchronization, A Minimum Output Range of 1/8192, and FE Memory
When used in combination with the Speedlite EL-1, the Speedlite Transmitter ST-E3-RT (Ver.2) provides additional benefits* of wireless rear curtain synchronization so the flash fires as the shutter closes to capture beautiful light trails to signify movement of the subject, minimum flash power as low as 1/8192 for even more opportunity to work in low available light, and FE memory so you can store an E-TTL flash exposure and continue to use that same exposure when subjects and scenes remain unchanged.

• Manual flash power below 1/128th not possible with 600EX-RT series, and 430EX-RT used as receiver units.
• 2nd curtain sync can be used with Speedlite EL-1, 600EX-RT series and 430EX-RT receiver units, but with EOS R5, R6, or EOS-1D X Mark III cameras only.

Up to 5 groups, or 15 Individual Flashes can be Controlled via 1 Transmitter
The Speedlite Transmitter ST-E3-RT (Ver.2) facilitates radio controlled, two-way wireless transmission up to 98.4 feet, for a reliable and robust connection among sender and receiver units. Communicating on 2.4 GHz frequencies, the ST-E3-RT (Ver.2) does not have the same directional limitations of traditional wireless optical transmitters. Where other wireless signals can be interrupted by physical obstacles, radio controlled systems excel. Fifteen transmission channels are available, selectable manually or automatically (for optimum radio transmission, depending on environment), and radio transmission IDs can be set to prevent interference from other photographers on the same channel. With the extended, more reliable range afforded by radio transmission, ambitious photography is made easier.

Supports E-TTL II Flash, Manual Flash, Stroboscopic and Auto External Flash Metering
With the Speedlite Transmitter ST-E3-RT (Ver.2), up to fifteen Canon RT-compatible Speedlites in five groups can be controlled from the camera, via a single transmitter. Each group can be set to a different flash mode, enabling multiple configurations for creative photography. For example, with the ST-E3-RT (Ver.2) some flashes can be directed to operate according to the camera’s E-TTL flash reading, others can be set manually; groups can be set to overexposure or underexpose, and much, much more. With up to fifteen flashes under the control of one transmitter, wirelessly, complex lighting setups normally reserved for the studio are a breeze.

Dot Matrix LCD Panel Displays all Pertinent Information Simultaneously and Backlit Control Panel means Easy Operation
The Speedlite Transmitter ST-E3-RT (Ver.2) features a dot matrix LCD panel (172 x 104 dots). This LCD displays Flash status, flash settings and wireless configuration for any combination of Speedlite EL-1, 600EX-RT series, and 430EX-RT, used off-camera as Receiver units. With the transmitter’s LCD screen combined with backlit operation buttons and even an internal sound emitter, the ST-E3-RT (Ver.2) is as easy to operate in the dark as in daylight.

8 Types of Custom Functions, 3 Types of Personal Functions
To accommodate the demands of a number of different shooting situations, the Speedlite Transmitter ST-E3-RT (Ver.2) can be configured with eight different Custom Functions and any of three Personal Functions. Custom Functions include: auto power off, modeling flash controls, sound, illumination and more. Personal Functions include display contrast and LCD panel illumination color for both sender and receiver flashes.

High-Performance Hot Shoe Contacts for Reliable Information Transmission and Operation
The Speedlite Transmitter ST-E3-RT (Ver.2) is built to the standards one would expect from professional Canon camera systems. The hot shoe contact ensures reliable communication between camera and transmitter. Dust and water resistance is excellent as well: all moving parts and areas surrounding the transmitter’s display and buttons are sealed for uninterrupted performance in harsh conditions. A dust and water resistant design for the mounting foot creates a dust and water resistant seal between camera and flash. Compact and lightweight, the ST-E3-RT (Ver.2) is approx. 2.7 (W) x 2.4 (H) x 3.0 (D) in.