Instruction Manual
Page 2
...), as a master unit or slave unit (430EX III-RT only) during radio transmission wireless flash shooting, and as a slave unit (430EX III-RT/430EX III) during optical transmission wireless flash shooting. Introduction The Canon Speedlite 430EX III-RT/430EX III is used as an on-camera flash that the Speedlite is an EOS-dedicated external Speedlite, compatible with E-TTL II/E-TTL autoflash systems. The Speedlite can be used with their operations.
...), as a master unit or slave unit (430EX III-RT only) during radio transmission wireless flash shooting, and as a slave unit (430EX III-RT/430EX III) during optical transmission wireless flash shooting. Introduction The Canon Speedlite 430EX III-RT/430EX III is used as an on-camera flash that the Speedlite is an EOS-dedicated external Speedlite, compatible with E-TTL II/E-TTL autoflash systems. The Speedlite can be used with their operations.
Instruction Manual
Page 98
... High-speed sync: Possible * During radio transmission wireless shooting, high-speed sync is not possible when using Type-B EOS cameras. Specifications Type Type: Compatible cameras: E-TTL II/E-TTL autoflash Shoe-mount Speedlite Type-A EOS cameras (E-TTL II/E-TTL autoflash) * Autoflash is possible only with EOS DIGITAL cameras released in and after 2012 (except with EOS REBEL T5/1200D).
... High-speed sync: Possible * During radio transmission wireless shooting, high-speed sync is not possible when using Type-B EOS cameras. Specifications Type Type: Compatible cameras: E-TTL II/E-TTL autoflash Shoe-mount Speedlite Type-A EOS cameras (E-TTL II/E-TTL autoflash) * Autoflash is possible only with EOS DIGITAL cameras released in and after 2012 (except with EOS REBEL T5/1200D).