[Brightcolours]

a7s & a7sii both do stunning full frame 4k. (admittedly crops to 16:9 from 4:3).

 

I think Canon have cheaped out by not implementing the hardware to properly do 4k by re-sampling the 30MPix image to 12. They also forgot to put on the appropriate encoder for h.265.

 

Its not like they have even done it for the 1dc. Having a 64Gb card fill up in 13 minutes really isn't usable.

The Sony A7's of course have 3:2 sensors, not 4:3.

The encoder stuff is kinda nonsense, as h.265 is nice for small file size end products, but sucks for source material. The Canon's 500mbit/sec mjpeg format blows all the Sonys and Panasonics out of the water, quality wise.

 

Just buy 256gb cards if you intend to shoot lots of 4K without wanting to switch cards.