Breaking news… The Sony A7S has been announced at NAB 2014.

It records 1080p internally in XAVC-S format at 50Mbit but the big news is the support for full 4K output via HDMI to an external recorder.

Unfortunately it does NOT have an internal 4K recording codec like the Panasonic GH4.

FULL PRESS RELEASE AS FOLLOWS:

Wide ISO sensitivity setting from 50 to 409600 and unprecedented dynamic range

World’s first full-frame sensor capable of full pixel read-out without pixel binning process for movie and 4K (QFHD: 3840 x 2160) HDMI video output

Professional video functions including XAVC S Full HD recording at 50Mbps, time code and optional XLR audio inputs

High ISO sensitivity range allows faster shutter speeds during low light shooting

α Mount System compatible with a wide range of high quality lenses, including power zoom lens ideal for movie shooting

Improved Fast Intelligent AF performance in light as low as EV-4

Ultra compact, light-weight body for comfortable pro-style operation

From starry night-time skies to atmospheric, candle-lit interiors: there’s now a camera that opens up extraordinary creative possibilities for capturing flawless, emotionally engaging movie footage and professional-quality still images.

Joining the acclaimed α7 and α7R – the world’s smallest full-frame interchangeable lens cameras – the α7S from Sony puts extraordinary sensitivity, low noise and spectacular 4K (QFHD: 3840×2160) image quality into the hands of serious photographers and videographers.

Equally suitable for still photography and cost-conscious movie production, the α7S delivers dramatic artistic possibilities in the smallest body of any full-frame interchangeable-lens digital camera in the world.

Key to the extraordinary sensitivity of the α7S is a specially developed new full-frame 35mm Exmor CMOS image sensor.

With a 12.2 effective megapixel count the size of each individual photoreceptive site is significantly boosted to increase their light-gathering power. Coupled with the camera’s powerful BIONZ X processing engine, this reduces image noise while increasing effective sensitivity range of the α7S to ISO 50 – ISO 409600 in expanded mode (ISO 200 – 409600 for movies).

This unrivalled sensitivity and ultra-low noise floor allows the α7S to capture beautiful images in low light conditions where a lengthy exposure would normally be needed. Thanks to the camera’s huge sensitivity, it’s possible to shoot crisp, low-noise stills and video using faster shutter speeds. Its immense dynamic range is also ideal for high-contrast scenes, effortlessly handling extreme highlights and rich, deep blacks in the same frame.

Because of the image sensor’s extraordinary sensitivity, the amount of light it can collect is dramatically increased compared with conventional cameras. The newly developed image sensor provides photographers/videographers with high dynamic range in all conditions from extremely low light to bright sunlight.

Using data read-out from every single pixel of the 35mm full-frame sensor (24p and 25p), 4K images created by the α7S are impressively detailed, with outstandingly rich colours and life-like textures in every frame. Refined by the BIONZ X processor, the high-speed data stream allows the α7S to output video at 4K resolution from the HDMI connector with 4:2:2 colour sampling, for recording onto an external storage device or viewing on a compatible monitor.

Thanks to the full pixel read-out from the whole of the 35mm full-frame sensor, there’s a notable absence of undesirable aliasing (moiré) effects and ‘jaggies’ that betray lower-resolution video. Stunningly clear images can be recorded on a memory card in Full HD quality with XAVC S[5] recording format at the 50Mbps data rate that’s highly regarded by professional videographers.

In APS-C crop mode, the α7S supports high frame rate shooting at 120fps or 100fps with HD resolution (1280 x 720 pixels). The 120fps footage can be played back at 24p for a 5x slow-motion effect – ideal for seeing every detail of sports action or the balletic grace of a dancer.

There’s a wealth of other specialist functions to please professional videographers such as Picture Profile™ for wide ranging visual expression and S-Log2 gamma. Time code/user bit functions allow pro-style editing workflow, while an optional XLR Adaptor Microphone Kit supports high-quality audio acquisition.

As already proven on the α7R, high-speed, high-precision Fast Intelligent AF has been further improved to fully exploit the new camera’s extraordinary low-light performance as low as EV-4. Other features familiar to α7 users include a high-contrast XGA OLED Tru-Finder, Wi-Fi/NFC connectivity and compatibility with the growing range of downloadable PlayMemories Camera Apps.

There’s a growing range of α lenses to take full advantage of the camera’s near-limitless creative potential. Currently under development, a brand-new full frame E-mount power zoom 28-135mm, F4 lens appeals to quality-conscious movie-makers. In addition, Sony is collaboratively working with third parties to support pro-quality 4K video workflow. A new XLR adaptor kit with a direct attachment mechanism is also under development.

The new α7S full-frame interchangeable lens digital camera from Sony will be available in Europe in summer 2014.