CANON - Camera Speedlite transmitter ST-E2

2CR5 lithium battery x 1
External battery : no

Flash
Type 550EX-dedicated, clip-on Speedlite transmitter with direct contacts
Compatible Cameras Type A EOS cameras (E- TTL, autoflash); Type B EOS cameras (Manual flash)
Sync Speed High-Speed Sync (FP flash): Enabled with high-speed sync mode
Flash Exposure Confirmation 1. Before flash fires during FE lock Adequate flash exposure indicated by the flash exposure level icon lit in the viewfinder. Insufficient flash exposure indicated by the flash exposure level icon blinking in the viewfinder.
2. After flash fires ST-E2's flash confirmation lamp lights in green for 3 sec.
AF Assist Beam Compatible with EOS-3's 45-point Area AF and 28mm and longer lens focal lengths
Effective Range: Approx. 0.6 to 10m/2.0 to 16.5 ft along the periphery (in total darkness).
Wireless Functions
Transmission System Infrared pulse
Transmission Range Indoors: Approx. 12-15 m/39.4 - 49.2 ft; Outdoors: Approx. 8-10 m/ 26.2-32.8 ft
Flash Ratio Control For A:B ratio: 1:8 to 8:1, in half- step increments or 13 steps
Flash Coverage Transmission Coverage: +/-40 degrees horizontal and +/-30 degrees vertical
Slave Operation Confirmation With test transmission button.
*Slave A fires followed by slave B at 1/64 output.
Slave Unit SE Mode Cancellation Cancels when the test transmission button or FE lock botton is pressed to turn on the slave unit.