Firmware Version 1.1.2 for the Canon EF 400mm f2.8L IS III USM lens and for the EF 600mm f4L IS III USM lens incorporates the following enhancement:
1. Increases the manual focus speed when the manual focus speed switch is set to 1 or 2.
*The speed when the switch is set to 3 (slowest speed) will be unchanged.
2. Improves the image stabilisation effect during handheld shooting with a slow shutter speed when used with EOS 5D Mark IV, EOS 6D, or EOS R.
*In addition, this firmware enables a full-time manual focus function during AI Servo AF when used with the EOS-1D X Mark II. The lens must be sent to the Factory Service Center in order for this function to be enabled.
If the lens' firmware is already Version 1.1.2, it is not necessary to update the firmware.
Before starting the firmware update procedure, please be sure to carefully read through and make sure you understand these instructions.
1. Increases the manual focus speed when the manual focus speed switch is set to 1 or 2.
*The speed when the switch is set to 3 (slowest speed) will be unchanged.
2. Improves the image stabilisation effect during handheld shooting with a slow shutter speed when used with EOS 5D Mark IV, EOS 6D, or EOS R.
*In addition, this firmware enables a full-time manual focus function during AI Servo AF when used with the EOS-1D X Mark II. The lens must be sent to the Factory Service Center in order for this function to be enabled.
If the lens' firmware is already Version 1.1.2, it is not necessary to update the firmware.
Before starting the firmware update procedure, please be sure to carefully read through and make sure you understand these instructions.
Firmware Updates for Canon EOS Bodies Go>>
