Speedlite Transmitter ST-E3-RT
The compact size and strong capabilities of the new Speedlite Transmitter ST-E3-RT 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. It has the same 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.
- Lightweight and affordable way to trigger one to 15 Speedlite 600EX-RT units for radio-based Wireless E-TTL
- Compatible for E-TTL automatic wireless flash with nearly all EOS Digital SLRs*, with all units firing at even power, or choice of A:B or A:B C flash ratios between groups of speedlites
- E-TTL, Manual flash, or Multi-mode manual flash possible with nearly all EOS Digital SLRs*
- Revolutionary new "Group" mode with newest EOS cameras -- EOS 5D Mark III, EOS-1D X, EOS 6D, Rebel T4i, etc** – independent control of up to five groups of off-camera Speedlite 600EX-RT units
* Original EOS-1D and EOS-1Ds are not compatible with Canon's radio-based wireless flash for automatic E-TTL exposure; Manual or Multi-mode flash only
** As of November, 2012