Canon Speedlite Transmitter ST-E3-RT is compact in size but with strong capabilities which make it almost a must-have for Speedlite 600EX-RT owners.
With the same radio-based wireless transmission abilities as a "master" 600EX-RT unit, it frees a Speedlite up for use off-camera, and can control up to fifteen flashes up to 98.4 feet (30m) off-camera and that's over a full 360° range. The Canon ST-E3-RT has thes ame advanced LCD panel and control as the 600EX-RT, and is powered by two AA-size batteries. Unlike the Speedlite Transmitter ST-E2, the ST-E3-RT is not compatible with the existing optical-type wireless flash system, and it does not have a built-in AF-assist beam.
The Canon ST-E3-RT is commonly used for Family photos, Portraits, Sports/action, Studio, Travel, Weddings and more.The Canon ST-E3-RT is most used by customers who consider themselves to be a Pro photographer among others.The Canon ST-E3-RT is popular because customers like the following qualities of the Canon ST-E3-RT: Durable, Easy to use, Lightweight, Packs small / compresses, Reliable, Strong construction and Superior build quality