Canon service program for tele, super tele lenses improves AF performance

Canon USA has today published a service advisory detailing a firmware update on four of its telephoto and super telephoto lens models for the pro market. In all four cases, the firmware updates autofocus algorithms for better responsiveness and more precise focus, especially when using AI servo AF to track irregularly-moving subjects.

The Canon EF 300mm f/2.8L IS II USM and EF 400mm f/2.8L IS II USM lenses were announced in August 2010, while the EF 500mm f/4L IS II USM and EF 600mm f/4L IS II USM announcements followed in February 2011. All four lenses faced significant delivery delays, in part due to the Tohoku earthquake and tsunami that struck Japan in early 2011. They eventually reached the market in late 2011, some six to eight months behind the original schedule, but the wait was worthwhile. While we've yet to review the 500mm and 600mm super teles, our sister site SLRgear.com's reviews of the 300mm tele and 400mm super tele found both to be quite spectacular. (Of course, we'd expect no less, with list prices ranging from US$7,300 to US$13,000!)

Today's firmware updates take all four lenses to firmware version 1.1.1, and are applicable to lenses with serial numbers in certain ranges, as below:

300mm: The third digit in the serial number is either 0, 1, 2, or 3 (xx0xxxxxxx,   xx1xxxxxxx,   xx2xxxxxxx,   xx3xxxxxxx).

400mm: The third digit in the serial number is either 0, 1, 2, or 3 (xx0xxxxxxx,   xx1xxxxxxx,   xx2xxxxxxx,   xx3xxxxxxx).

500mm: The third digit in the serial number is 0 (xx0xxxxxxx).

600mm: The third digit in the serial number is 0 (xx0xxxxxxx).

The firmware updates must be applied by a Canon service center, and customers with lenses needing the updates should contact their local Canon agent for assistance. In the US market, contact details are as follows:

Phone: 1-800-OK-CANON (1-800-652-2666)
TDD: 1-866-251-3752
Email:  [email protected]

Canon's EF 500mm f/4L IS II USM (top) and EF 600mm f/4L IS II USM (bottom) lenses. Photos provided by Canon Inc.