This afternoon Canon posted a service notice on its website for owners of the company's 1D Mark III digital SLR. If you haven't been following the saga of the camera's autofocus problems, Canon admitted a couple of weeks ago that some of that model's units have a problem with the submirror, a small mirror that sits behind the main mirror and helps to divert light to the AF system. As a result, they can end up with inaccurate focus and/or inaccurate focus tracking in AI-Servo AF and continuous shooting modes. The problems are supposedly more prevalent when shooting in high temperatures. At the time, the company was still trying to figure out how it would address the issue and told owners to stay tuned for further updates. Now, they have said that they will begin to offer free repairs for owners experiencing this problem toward the end of this month and will post specific details to their Web site when they become available.
According to the service notice, the problem is limited to cameras with serial numbers between 501001 and 546561. However, they say that the problem doesn't affect all the cameras in that range. Indeed, while our review sample was in that range, I was never able to recreate the issue, despite shooting on some days with temperatures in the high 90s. If you live in the USA or Puerto Rico and would like to speak to someone at Canon's customer service center about this issue, you can call 800-828-4040. Owners in other parts of the world should contact their local Canon customer service center.