Canon has made Canon EF 400mm f/4 DO IS II USM Lens firmware update version 1.0.9 available for download.
Firmware Version 1.0.9 incorporates the following fixes and enhancements:
Camera Gear Review News Photo Tips & Stories ▸Archives
Canon News Announcements Firmware Updates Service Notices Digital Photo Pro
Sony News Announcements Firmware Updates
Sigma Tamron
Deals & Shopping News Photography Deals (No Deals) Canon Refurbished Canon Rebates Sony Rebates Tamron Rebates Sigma Rebates