Canon SPEEDLITE 90EX Manual De Instrucciones página 16

• Shutter sync. (1st curtain*/2nd curtain)
- 1st curtain:
- 2nd curtain:
• Flash exp. comp
You can adjust the flash output level in the same way as normal exposure
compensation.
• E-TTL II (Evaluative*/Average)
- Evaluative:
- Average:
• Wireless functions (Off*/Optical transmission) (p.15)
• Optical channel (1* to 4)
• Flash group (ALL, A:B, A:B C)
• Group exposure compensation (A, B, C)
• Ratio control (8:1 - 1:8, 1/2-stop increments)
 [Flash C.Fn settings]
1: Auto power off (Enabled*/Disabled)
14
This is the normal flash shooting mode in which the flash fires at the
timing when the shutter is fully open.
The flash fires right before the shutter closes.
Fully automatic flash shooting can be performed, from dark scenes
to fill-flash shooting.
Metering is averaged for the entire scene.