We're continually receiving more information about C-Log being added to the Canon EOS 5D Mark IV.
We're now told by a separate source that adding C-Log to your EOS 5D Mark IV may require a quick trip to Canon service, and that it's not as simple as just a firmware update. There is no mention whether or not this will be a service you will have to pay for or not, or if future EOS 5D Mark IV cameras will ship with the feature.
While we cannot confirm this information at present, we wouldn't be surprised.
We haven't received any more information about any other features coming to the EOS 5D Mark IV with this upgrade. We also haven't heard if the Canon EOS-1D X Mark II will also get this upgrade.
More to come…