Following the recent forum posting by a moderator in Canon’s official forums, Canon has issued a product advisory concerning the slow AF speed for the 5D Mark III and 1D X when using a Speedlite AF assist beam.
Firmware updates to address this issue are expected for the 5D Mark III and 1D X in April 2013 and May 2013, respectively.
The full product advisory from Canon is reproduced below.
Thank you for using Canon products.
EOS 5D Mark III Digital SLR Camera
EOS-1D X Digital SLR Camera
Depending upon the shooting conditions, it may take slightly longer for the EOS 5D Mark III and EOS-1D X digital SLR cameras to acquire focus when using the Speedlite’s AF Assist Beam, compared with that of the EOS 5D Mark II and EOS-1D Mark IV digital SLR cameras using the Speedlite’s AF Assist Beam.
We are developing a solution to enhance the focusing feature for the EOS 5D Mark III and EOS-1D X and plan to release a firmware update based on following estimated schedule:
EOS 5D Mark III: (estimated) Late April, 2013
EOS-1D X: (estimated) Late May, 2013
This information is for residents of the United States and Puerto Rico only. If you do not reside in the USA or Puerto Rico, please contact the Canon Customer Support Center in your region.
If you have not already done so, please register your Canon EOS 5D Mark III Digital SLR Camera or your Canon EOS-1D X. Digital SLR Camera. By registering, we will be able to notify you via email about future service upgrades.
Customer Support Operations
Canon U.S.A., Inc.
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