Canon today has published a service notice advising owners of the EF 24-105mm f/4L IS that this lens can exhibit a pronounced flare problem with point light sources. A repair program will commence on November 14, 2005, enabling 24-105mm f/4L IS owners to send in the lens for an unspecified parts replacement. In the USA, both the repair itself, and shipping costs, are being absorbed by Canon.
Except for the reduction or elimination of a particular flare condition, the optical characteristics of the EF 24-105mm f/4L IS are not expected to be altered by the repair, says Chuck Westfall, Director of Media and Customer Relationship at Canon USA. In addition, the lens prior to the repair will perform as designed except when scene lighting conspires to reveal the flare problem. This is consistent with our experience with the EF 24-105mm f/4L IS, which we've used extensively for several weeks.
The service notice details how an owner of this lens can identify, by the lens' control number stamped near the rear element, whether it's one that needs to be repaired. If the control number, which starts with UT, is less than 1000, it's a repair candidate. All units of this new lens model, however, that have shipped since it began to emerge on store shelves in late August 2005 are affected, says Westfall. At this point, checking the control number will mainly provide confirmation that the lens needs to be sent to Canon starting the middle of next month. Dealers have been asked to return any inventory of this lens as well, though it's unlikely that there are too many units of the EF 24-105mm f/4L IS idling on retail shelves.