Canon EOS-1D X Mark III EOS-1DX Mark III Advanced User Guide - Page 373

[ 3] Electronic full-time MF Operation of manual focus adjustment using the electronic focusing ring when certain lenses are attached is customizable. Check the Canon website for compatible lenses. Disable Operation of manual focus adjustment corresponds to the [Lens electronic MF] setting. Enable Manual focus adjustment is available whenever camera operations are possible (fulltime manual focus). Lens electronic MF For EF lenses equipped with electronic manual focusing, you can specify how manual focus adjustment is used with One-Shot AF. [ ] Disable after One-Shot After the AF operation, manual focusing adjustment is disabled. [ ] One-Shot→enabled You can manually adjust the focus after the AF operation if you keep holding down the shutter button halfway. 373