Web Announcement originally posted on 18th Jan 2012. Revised 2nd December 2019.
Thank you for using Canon products.
It has been confirmed that, even when the lock screw for the lens hood on the Lenses is fastened, the lens hood may rotate when a certain amount of pressure is applied, but it will not detach from the lens. As a result, some specifications for the lens hood have been changed to address this phenomenon.
For customers who may be inconvenienced by this phenomenon during shooting and would like to request a lens hood exchange, please contact the Canon Customer Support center in your region. The details are as follows.
Lens hoods for EF300mm f/2.8L IS II USM and EF400mm f/2.8L IS II USM interchangeable lenses for Digital SLR Cameras.
Serial number: 770ｘｘｘｘｘｘｘ through 841ｘｘｘｘｘｘｘ
And, units with serial numbers in which the 4thdigit is “0” are also affected.
For customers who would like to request a lens hood, please contact your nearest Canon Customer Support center for a lens hood free of charge.
Our free exchange service starts from 19/01/2012
Contact Information for Inquiries
Australia: Call 13 13 83
New Zealand: Call 0800 222 666