There are only a few consumer-level options for shooting 4K video, but Sony clearly has a plan for stepping forward and bring the goods in this department. The new AX100 camcorder not only shoots 4K, but has a host of other awesome-sounding specs to attract video shooters.
Not many people are buying camcorders anymore, most just use their phones or DSLRs. But with a headline feature like 4K, companies like Sony are hoping to draw people back to the days of dedicated video devices. In 2013 they released the AX1, a £3,800 4K Handycam. The problem was it's size and specs. Too big for casual shooters, with a small sensor for flat-looking video. The AX100 remedies both those flaws.
Within a sleek looking, compact black frame is a one-inch Exmor R CMOS sensor, the same one found on the RX100 II compact still camera. That makes for better low-light performance and more control over depth-of-field. The sensor has proven itself in the video of the RX10, and with the AX100, we are excited to see what the 3840 x 2160 resolution video at 30p or 24p will look like.
The AX100 will feature a Carl Zeiss Vario Sonnar T* lens...with a f/2.8-4.5 aperture and 12x optical zoom. There is a focus ring for manual focus as well as peaking on the 3.5 inch 921-thousand dot touch-screen LCD.
The exterior is simple and functional, with a decent set of manual controls including a wheel and buttons to switch the function between iris, iso, and shutter speed. Finding critical focus in a 4K image can be difficult, so Sony included a helpful dedicated focus magnifier button for punching in and tweaking. Three levels of ND filter will make it easy to shoot in bright sunlight at wide apertures for those shallow focus shots.
Footage will be encoded using the XAVC-S codec and record to Class 10 SDXC cards. The insane levels of compression required to force all that data through to an SD card is bound to wreak havoc on video detail. Just like the AVCHD codec can leave artefacts and mud in the details of 1080p video, expect the same to occur out of the AX100. This is the main weakness of tackling 4K at the consumer level at this point in time. The sheer volume of data is tough to deal with in terms of transmission and storage. The recently introduced Bionz X processor should help with manage the data flow.
For those who have no use for the uber-resolution of a 4k spec, Sony is offering essentially the same exact camcorder that only shoots HD video—the CX900. It will be interesting to see how the CX900 measures up against the RX10, which shoots stills as well as video, but has the same sensor and processor as the CX900. One advantage is that the CX900 will record at a data rate of 50 Mbit/s, thanks to the XAVC-S codec, while the RX10 only records at 28 Mbit/s in AVCHD. That hopefully means less artifacts and muddy details. Also, the new camera is capable of 120 fps recording for smooth slow motion.
The AX100 4K camcorder will be available in March for $2000 in the US (Sony hasn't confirmed the UK pricing yet), while the HD-only CX900 will go for $1500. Sony has an upward battle ahead of them because 4K is bound to make it's way into DSLRs in the near future, which may entice creative-types more than the traditional camcorder form factor that, frankly, seems rather old-hat nowadays.