Canon has issued firmware v1.1.3 for the EOS 5D Mark III, which adds support for the EF 40mm f/2.8 STM and fixes bugs related to Auto Lighting Optimizer, the rear LCD and the use of certain supertelephoto lenses with teleconverters attached. Various language mistakes in the camera's menus have also been corrected.
Firmware Version 1.1.3 incorporates the following improvements and fixes:

1. Supports the single focal length EF40mm f/2.8 STM lens that is to be released at the end of June, 2012.
2. Fixes a phenomenon in which an image may become underexposed when using the Auto Lighting Optimizer for continuous Auto Exposure Bracketing (AEB) shooting.
3. Fixes a phenomenon in which the backlight of the LCD monitor may not turn off depending on the camera settings and timing.
4. Fixes a phenomenon in which the camera's power may not turn on when a super-telephoto lens (#1) is mounted to the camera with an extender (#2).

*1) EF 300mm F2.8L IS II USM / EF 400mm F2.8L IS II USM
*2) Extender EF 1.4X III / Extender EF 2X III

5. Corrects mistakes in the Dutch, Italian, Korean, Norwegian, Polish, and Swedish menu screens.

Download it from here.

Anyone else have trouble downloading this using Firefox 13.1? I had to switch over to Internet Explorer to get access to the file.

No trouble with download via Safari, no trouble with installation.
I was disappointed to see that there's no attempt to tweak the AF illumination options.
I may have immediately found a bug in the FW: it changed my setting for using the Set button to magnify the image. I redid my custom setting (via the Q button), but after one shoot and review it reverted to review of full image when pressing Set. I made the change again, and it seemed to "stick".

I don't plan to get the 40/2.8.
I shoot raw so I haven't noticed any glitches in auto lighting optimizer.
Hadn't noticed any problems with the LCD backlight.
My EF 300mm F2.8L IS II USM with Extender EF 2X III has worked flawlessly before the FW update.
Maybe I'll use the Italian menu for practice, to justify having done this update.

I havent noticed any changes since updating.

markdh wrote:
Anyone else have trouble downloading this using Firefox 13.1? I had to switch over to Internet Explorer to get access to the file.

No trouble with Firefox here but I think I'm using 13.0

Photon wrote:
I may have immediately found a bug in the FW: it changed my setting for using the Set button to magnify the image. I redid my custom setting (via the Q button), but after one shoot and review it reverted to review of full image when pressing Set. I made the change again, and it seemed to "stick".

I have mine set the same way and the update did not effect it...


Photon wrote:Maybe I'll use the Italian menu for practice, to justify having done this update.