The Canon Speedlite Transmitter ST-E2 is a dedicated E-TTL (II) wireless autoflash transmitter that can control an unlimited number of 420EX, 550EX, 580EX, or MR-14EX and MT-24EX flashes, in up to three separate groups; A, B, and C.

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 can not be used as the master slave to trigger other flashes

Key Features:

• Compatible with 420EX, 550EX, 580EX, or MR-14EX and MT-24EX Macro 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