The Canon Speedlite Transmitter ST-E2 is a dedicated E-TTL (II) wireless autoflash transmitter that can control an unlimited number of 420EX, 430EX, 550EX and 580EX flashes, 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 EOS-3's 45 focusing points.

Note: 420EX/430EX can not be used as the master slave to trigger other flashes.

Compatible with 420EX, 430EX, 550EX, and 580EX flashes

Compatible Cameras: Type A EOS cameras (E- TTL, autoflash); type B EOS cameras (Manual flash)

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