Yongnuo YN568EX Instructions Manual page 30

Fn NO.: E3
L cd 7/15/30：The display time of LCD backlight is 7/15/30 seconds
Fn NO.: E4
I nc 0.3：0.3ev for fine-tuning step
I nc 0.5：0.5ev for fine-tuning step
I nc on：Mix 0.3ev and 0.5ev for fine-tuning step
Fn NO.: E5
CL EA﹣﹣：Recover the default settings