Canon 550EX manual Specifications, 119

Specifications

Flash-ready indication: (1) Red pilot lamp indicates normal flash ready.

(2)Yellow pilot lamp indicates quick flash ready. AF-assist beam linkage and range:

Linked to area AF (45 focusing points), effective from approx. 0.6 to 10 meters / 2 to 33 feet at the center and 0.6 to 5 meters / 2 to 16 feet along the periphery (in total darkness).

Wireless functions
Transmission system: Optical pulse transmission
Configuration:	Camera, master unit, and slave unit(s)
Wireless switchover:	With wireless selector
Wireless selector positions:
	OFF, Master, Slave
Channels:	4
[Master unit]
Transmission angle:	Horizontal: Approx. 80° / Vertical: Approx. 60° (At		zoom setting)
	(Manual zooming of flash head also enabled)
Transmission range:	Indoors: Approx. 12 to 15 meters / 39.3 to 49.2 feet
	Outdoors: Approx. 8 to 10 meters / 26.2 to 32.8 feet
No. of transmissions:	Approx. 1500 (without master unit firing)
Controllable slaves:	A, B, C (3 groups)
Flash control:	(1) E-TTL autoflash (with Type-A cameras)
	High-speed sync (FP flash) / FE lock / flash exposure compensation /
	FEB / flash ratio control
	(2) Manual flash (with Type A and B cameras)
	(3) Stroboscopic flash (with Type A and B cameras)
Flash ratio control:	A:B = 8:1 to 1:1 or 1:1 to 1:8 (In thirteen 1/2-stop increments)
	(For C, flash exposure compensation can be set up to ±3 stops in 1/3 or
	1/2-stop increments.)
Master flash:	ON/OFF possible (When ON, automatic set as slave unit A.)
[Slave unit]
Reception angle:	Horizontal: Approx. 80° / Vertical: Approx. 80°
Flash coverage:	Set automatically to	(Manual zooming of flash head also enabled)
Flash-ready indication:	AF-assist beam emitter blinks
Flash modes:	(1) Controlled automatically by master unit.
	(2) Manual flash and stroboscopic flash settable independently from master
	unit.

Flash exposure compensation:

Settable individually with each slave unit up to ±3 stops in 1/3- or 1/2-stop increments.

Slave Operation Confirmation:

Enabled with master unit's test firing button.

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