The Canon ST-E2 Speedlite Transmitter is a dedicated E-TTL (II) wireless autoflash transmitter that can control an unlimited number of flashes with Canon Speedlites 420EX, 430EX, 430EXII, 550EX, 580EX and 580EX in two separate groups; A and B.
The ST-E2 sets and controls all functions of its slave units. The flash output ratio between groups A and B can also be adjusted from 8:1 to 1:1 or from 1:1 to 1:8.
Under low-light or low-contrast conditions it emits an AF-assist beam linked to the camera's focusing points.
Note: 420EX/430EX cannot be used as the master slave to trigger other flashes.
Compatible Canon Speedlites 420EX, 430EX, 430EXII, 550EX, 580EX and 580EX II
Compatible Cameras: Type A EOS cameras (E- TTL, autoflash); type B EOS cameras (Manual flash).
Compatible models include: EOS 1D Mark II N, 20D/60D/70D EOS-1Ds MARK II, EOS 5D Mark III, PowerShot G3, PowerShot G5, PowerShot G6, PowerShot G7 and PowerShot G9
Flash Ratio Control: For A:B ratio: 1:8 to 8:1, in half- step increments or 13 steps
High- Speed Sync (FP flash): Enabled with high-speed sync mode
Slave Operation Confirmation: With test transmission button. *Slave A fires followed by slave B at 1/64 output
AF-assist Beam: Compatible with EOS-3's 45-point Area AF and 28mm and longer lens focal lengths
SE Feature: While the power switch is set to I or HOLD, the transmission turns off automatically after about 90 sec. of non-use
Indoors: Approx. 39.4 - 49.2' (12-15 m)
Outdoors: Approx. 26.2-32.8' (8-10 m)