New Firmware Update for Some Canon Super-Telephotos

Canon has released a firmware update for the EF300mm f/2.8L IS II USM, EF400mm F2.8L IS II USM, EF500mm f/4L IS II USM and EF600mm f/4L IS II USM lenses. This firmware update will be performed by Canon Service Centers.

Firmware Version 1.1.1 changes the control algorithm of the focus drive, and enhances the drive’s responsiveness for more precise focus and adjustments. In particular, the new firmware enhances the AI servo AF capability of the lenses to track objects that move irregularly in sports events, such as soccer or rugby.
Affected Products :
 Firmware Version 1.1.1 is for lenses with Firmware Version 1.0.0. If the lens’ firmware is already Version 1.1.1, it is not necessary to update the firmware.

The serial numbers (10 digits) of the lenses equipped with Firmware Version 1.0.0 are as follows:
EF300mm f/2.8L IS II USM :
 The third digit in the serial number is either 0, 1, 2, or 3 (xx0xxxxxxx, xx1xxxxxxx, xx2xxxxxxx, xx3xxxxxxx).
EF400mm f/2.8L IS II USM :
 The third digit in the serial number is either 0, 1, 2, or 3 (xx0xxxxxxx, xx1xxxxxxx, xx2xxxxxxx, xx3xxxxxxx).
EF500mm f/4L IS II USM
 : The third digit in the serial number is 0 (xx0xxxxxxx).
EF600mm f/4L IS II USM : 
The third digit in the serial number is 0 (xx0xxxxxxx).
Lenses with serial numbers other than those listed above are equipped with Firmware Version 1.1.1 or later.