This firmware update (Version 1.1.3) incorporates the following improvements and fixes:

1. Increases transmission speed when using high-speed SD cards. Through the efforts to accelerate transmission, the speed of writing images to or reading images from high-speed SD cards is made faster. *Depending on the SD cards you use, there may be no difference.
   
2. Fixes a phenomenon involving not being able to release the shutter. Depending on the timing at which the AF-ON button and shutter release button are pressed, in rare cases the shutter could not be released; but this phenomenon has been fixed.
   
3. Improves AF tracking in specific conditions. a) Improves AF tracking when shooting outdoors in bright environments. b) Improves AF tracking of low-contrast subjects. *The improvements described in a) have been incorporated since Firmware Version 1.1.1. The improvements described in b) are new to Firmware Version 1.1.3.
   
4. Corrects errors in the Spanish and Korean menu screens. There were errors in the Spanish wording of some of the C.Fn items and in the wording of messages that appear in Korean during firmware updates, but those have been corrected. *The errors described above that appear in Korean during firmware updates will be corrected after this update is completed.
   

The Version 1.1.3 firmware being released this time is for cameras with firmware up to Version 1.1.1. If the camera's firmware is already Version 1.1.3, it is not necessary to update the firmware.

Visit the Canon EOS-1D Mark III firmware download page for more info and instructions.