Sony US just announced the new 12 Megapixel Full Frame E-mount A7s camera. In short these are the bad and good news:
Bad:
– Unlike the Gh4 it doesn’t record 4K on SD cards. You have to buy and sue an external recorder to record 4K 4:2:2 video.
– Autofocus hasn’t been improved (why not add the amazing A6000 hybrid AF?).
Good:
– Low resolution sensor allows amazing 409,600 ISO.
– Sony says this si the FF sensor with the highest dynamic range and color fidelity
– Costs just like the Panasonic GH4 ($1699)
Full specs and details and image/video samples at SonyAlphaRumors.