Yongnuo YN568EX User Manual

S1 and S2 modes are suitable for MANUAL flash environment and TTL flash environment respectively. Under
these two modes, the way to adjust the output level is like that in M mode.
S1 mode: It will work with the first work of the master flash synchronously,
with the result consistent with the use of radio slave. To use this mode
correctly, the master flash should be set at manual flash and the TTL flash
system with preflight function and the red-reduction function with multiple
flashes should not be used.
S2 mode: It is also called “pre-flash cancel mode”. This mode is similar with
S1 mode, but it can neglect the pre-flash given by TTL flash. Therefore, it
can support the main flash working in TTL mode. In particular, if S1 mode
cannot flash correctly and synchronically with your internal flash, you can try
to use S2 mode.
The following situation shall be avoided when the S1 and S2 modes are used:
the red eye reduction function of the main light is used; the order mode
(nikon) or wireless mode (canon) of the main light is used; the ST-E2 is used as the flash controller. Otherwise,
please set the speedlite as Sc/Sn.

Yongnuo YN568EX Specifications

General

Flash Modes	TTL, Manual, Multi
Zoom Range	24-105mm
Recycle Time	Approx. 3 seconds
Power Source	4 x AA batteries
High-Speed Sync	Yes
Color Temperature	5600K
Swivel Angle	270 degrees
Guide Number	58 (at ISO 100, 105mm)
Vertical Rotation Angle	-7 to 90 degrees
Horizontal Rotation Angle	0 to 270°
Compatible Cameras	Canon or Nikon (depending on the version)
Tilt Angle	-7 to 90 degrees
Wireless Functionality	Yes, Master & Slave (Canon & Nikon)
Weight	380g (without batteries)