Canon EOS-1Ds Mark III EOS-1Ds Mark III Instruction Manual - Page 166

3 Custom Function Settings C.Fn III: Auto focus/Drive C.Fn III -1 USM lens electronic MF USM lens electronic MF can be enabled or disabled for when you use any of the following lenses. EF50mm f/1.0L USM, EF85mm f/1.2L USM, EF85mm f/1.2L II USM, EF200mm f/1.8L USM, EF300mm f/2.8L USM, EF400mm f/2.8L USM, EF400mm f/2.8L II USM, EF500mm f/4.5L USM, EF600mm f/4L USM, EF1200mm f/5.6L USM, or EF28-80mm f/2.8-4L USM 0: Enable after One-Shot AF After focus is achieved in One-Shot AF, electronic MF is enabled. If C.Fn IV -1-2, 3 is set, it is also enabled before focus is achieved. 1: Disable after One-Shot AF After focus is achieved in One-Shot AF, electronic MF is disabled. If C.Fn IV -1-2, 3 is set, it is possible before focus is achieved. 2: Disable in AF mode Electronic MF is disabled in the AF mode. C.Fn III -2 AI Servo tracking sensitivity During focusing in the AI Servo AF mode, the AF sensitivity for tracking subjects (or obstacles) moving into AF points can be set to one of five levels. If it is set toward [Slow], interruptions by any obstacles will be less disruptive. It makes it easier to keep tracking the target subject. If it is set toward [Fast], it will be easier to focus any subjects which suddenly enter the picture from the side. Convenient when you want to successively photograph multiple subjects located at random distances. C.Fn III -3 AI Servo 1st/2nd image priority For the AI Servo AF and continuous shooting modes, you can change the Servo's operation characteristics and shutter-release timing. 0: AF priority/Tracking priority For the first shot, focusing the subject is given priority. For the 2nd and following shots during continuous shooting, focus-tracking of the subject is given priority. 166