Canon Speedlite 550EX is the main component of a new flash system designed together with the EOS-3 SLR camera. It provides full compatibility with the new area AF technology employed by the EOS-3 and refined E-TTL autoflash for improved performance. Other main features include a maximum Guide Number of 180 (ISO 100, ft.), an AF-assist beam which links to the EOS-3's 45-point area AF, FP Flash (high speed sync), FE lock (a flash version of AE lock), and FEB (Flash Exposure Bracketing). The Speedlite 550EX also incorporates a built-in wireless transmitter, which can control other Speedlite 550EX units set up as slave units. Flash coverage is set automatically from 24mm to 105mm, and a wide-angle panel extends the coverage to 17mm. The new Speedlite runs on 4 AA-size batteries, and can also be used with optional external power supplies such as Compact Battery Pack E and Transistor Pack E. Recycling times are similar to those experienced with the Speedlite 540EZ. Speedlite 550EX is compatible with all EOS models.
The most impressive feature of the 550EX, however, is its ability to support a wireless multiple flash system which allows photographers to set up unlimited numbers of additional Speedlite 550EX flashes as slave units while controlling their flash output from the camera position. Even when using multiple Speedlites, photographers can utilize all of the 550EX's advanced features including E-TTL, FP flash, FE lock and Flash Exposure Bracketing (FEB).
All 550EX controls are located on the rear of the unit, including a Master/Slave switch, indicating whether the flash will be used as a Master (on the camera's hot shoe) or as a remote Slave. The remote flash system permits photographers to set up as many as three groups (designated A, B or C) of 550EX Speedlites set up as slave units with virtually unlimited numbers of flash units possible within each group.
When using the EOS-3 with multiple Speedlite 550EX flash units, or when shooting with E-TTL wireless autoflash using the Speedlite 550EX in conjunction with the wireless Speedlite Transmitter ST-E2, the output ratio of two different slave groups can be set on the master unit. The A:B flash ratio can be set to any of thirteen half-step increments ranging from 8:1 to 1:8. Flash exposure compensation for slave group C can be set on the master unit in 1/3 or 1/2 stop increments up to +/- 3 stops. This is ideal for background or accent lighting when shooting portraits in a studio setting, for example. Power output for each Slave unit can be controlled directly from the Master flash or Speedlite Transmitter ST-E2, eliminating the need to adjust each Slave unit from its remote location. In addition, the system offers a "modeling lamp" function which gives photographers a good idea of how lighting will fall on the subject. The wireless remote flash system has a range of approximately 35 feet when used outdoors and approximately 50 feet indoors. Each slave unit, when signalled by a test flash from the Master Unit, indicates its readiness in ascending order according to its assigned group, giving photographers the ability to verify that the slave units are within range and functioning properly. An LED indicator on the back of the Master Unit acts as a flash exposure confirmation signal, and is fully effective even in wireless multiple flash setups.
Canon Speedlite Transmitter ST-E2
Canon's wireless Speedlite Transmitter ST-E2 is ideal for use by photographers who do not need to have any light source emanating directly from the camera position, but wish to utilize the system's remote flash capabilities. Mounted on the hot shoe of the camera, the wireless transmitter serves as the Master, controlling the functions of up to two groups of 550EX Slave units. Like the 550EX, the ST-E2 also has a built-in AF-assist beam which is linked to the EOS-3's area AF.
The new Canon Speedlite 550EX flash and Wireless Transmitter ST-E2 will be available in USA at Canon authorized camera dealers in early December.
