I cannot get this off Google or the manual.
At least, not without $80 more coffee and facepalming.

How the heck do you enable the 4k HDMI output? Mine is greyed out and despite all the combinations I run through, nothing enables it. The camera was new around Nov 2014.

Thanks!

It may be an EDID issue - have you set the record format on the recorder (I assume it is your new Shogun) first? 4k is new enough you may need to "force" the EDID handshake.

Starting around 25 minutes on this video:

Atomos Shogun meets Sony A7S in 4k & GH4 get 10bit 4:2:2 and more... on Vimeo

It just popped up for me. Hmmm...