Atomos have just sent me some info on their upcoming 4K recorder, primarily for use with the A7S and GH4.
The Shogun is a 7″ IPS monitor backed with recording capability. It is the only 4K HDMI recording solution that can take advantage of the A7S’s 4K signal, 120fps HD output and custom HDMI timecode with start / stop trigger.
The Shogun also has 12G SDI ports and will record 4K ProRes onto single SSDs or RAID.
The recorder will be priced under $2k.
The Shogun also allows uncompressed raw Cinema DNG capture, although I believe this is over HD-SDI only.
The release date for this recorder is not until end of Q3 / Q4 2014, so potentially GH4 and A7S owners could have a while to wait for glorious 4K over HDMI.
On the GH4 this will be a 10bit output to a 10bit ProRes file.
On the A7S this will be an 8bit output to a 10bit ProRes file. so the GH4 maintains an upper hand here as well as that much lighter footprint of the internal 100Mbit codec, for file sizes 8x less than 4K ProRes.
I am super excited for both quite frankly.
The A7S promises an absolutely amazing full frame 4K image, and the GH4 has the more complete feature set and is more practical to use straight off the bat.