3Custom Function SettingsN
C.Fn-7 Mirror lockup
0:Disable
1:Enable
Effective for close-up and telephotos shots to prevent camera shake caused by the mirror’s reflex action. For more on mirror lockup, see page 94.
C.Fn-8 E-TTL II
0:Evaluative
Fully automatic flash photography under all conditions, from low light to daylight fill-flash.
1:Average
The flash exposure is averaged for the entire area covered by the flash. Since the camera will not execute automatic exposure compensation, adjust the flash exposure compensation if necessary. This also applies if you use FE lock.
C.Fn-9 Shutter curtain sync.
0:1st-curtain sync.
1:2nd-curtain sync.
When a slow shutter speed is set, you can capture a light trail following the subject.The flash fires right before the shutter closes. This Custom Function can be used to obtain 2nd-curtain sync effects even with EX-series Speedlites which do not provide 2nd- curtain sync. If the EX-series Speedlite has this feature, it will override this Custom Function.
When 2nd-curtain sync is used, a preflash will be fired for flash metering control right after you press the shutter button completely. Remember that the main flash will fire right before the shutter closes.