Canon EOS 5D Mark III Instruction Manual (en)

 Menu Function Settings
Silent LV shootingN
This function applies to still photo shooting. For details, see page 
Metering timerN
You can change how long the exposure setting is displayed (AE lock 
[z5] Menu
Time code
You can set the time code. For details, see pages 239-242.
Silent Control
When [Enable h] is set, you can use the touch pad <h> and 
Quick Control screen to change settings silently during movie 
shooting. For details, see page 238.
Movie shooting button
When [V/
] is set, besides pressing the <0> button, you can 
also press the shutter button completely or use Remote Switch RS-
80N3 (sold separately) or Timer Remote Controller TC-80N3 (sold 
separately) to start/stop the movie shooting (p.187). However, when 
] is set, still photo shooting is not possible (p.230).