From Canon USA:
We would like to inform you that release of firmware to enhance functions of the EOS 5D Mark IV, which was originally scheduled for November 29 at the same timing as the firmware updates for six other models (EOS-1D X Mark II: Ver.1.1.4; EOS-1D X: Ver.2.1.0; EOS 5D Mark III: Ver.1.3.5; EOS 5DS: Ver.1.1.2; EOS 5DS R: Ver.1.1.2; EOS 6D Ver. 1.1.8), has been postponed until late February 2018 for reasons related to firmware preparation. We would like to offer our sincere apologies to users of this product who have been inconvenienced.
In the firmware to enhance functions of the EOS 5D Mark IV, we are planning to incorporate the following enhancements:
- Support will be added for chromatic aberration correction, peripheral illumination correction, distortion correction, and Digital Lens Optimizer when using Digital Photo Professional to process RAW images captured with the following TS-E lenses: TS-E 17mm f/4L, TS-E 24mm f/3.5L II, TS-E 50mm f/2.8L MACRO, TS-E 90mm f/2.8L MACRO, or TS-E 135mm f/4L MACRO.
- Support will be added to fix a phenomenon* in which standard exposure may not be obtained, or an irregular exposure may result, when Silent LV (Live View) shooting with the following TS-E lenses: TS-E 50mm f/2.8L MACRO, TS-E 90mm f/2.8L MACRO, or TS-E 135mm f/4L MACRO.
- Support for Exif 2.31 will be added.
*This phenomenon occurs when tilt or shift is applied on a TS-E lens (TS-E 50mm f/2.8L MACRO, TS-E 90mm f/2.8L MACRO, or TS-E 135mm f/4L MACRO) during LV shooting when Silent LV shooting is set (set to Mode 1 or Mode 2 on the menu). For this reason, until the firmware update, when performing viewfinder shooting or LV shooting, please shoot with the Silent LV shooting set to [Disable].