X-OCN: Maximum quality, moderate bitrates.
The world of digital cinematography is changing. Distribution channels are increasingly calling for 4K resolution, High Frame Rates, Wide Color Gamut and High Dynamic Range – all of which are data intensive. Yet productions still require reasonable transfer times and affordable storage, not to mention long camera loads. To meet all these requirements, Sony developed a fresh and powerful solution. Presenting eXtended Tonal Range – Original Camera Negative, X-OCN, exclusively available on Sony’s AXS-R7 recorder. By combining superlative 16-bit precision with surprisingly moderate bit rates, X-OCN opens up powerful new production possibilities.
The power of 16 bits
Like other codecs, X-OCN produces file sizes much smaller than typical camera RAW, resulting in longer record times, faster file transfers and more economical postproduction. But unlike conventional codecs, X-OCN offers 16-bit scene linear encoding. The quality of 16-bit X-OCN far exceeds 10- or even 12-bit formats – often at lower bit rates. 16-bit recording means roughly 65,000 tonal gradations per channel and 65,0003 or 280 trillion individual shades of color. As a result, you get the ultimate in tonal expression, for powerful High Dynamic Range whether you’re using S-Log3, SMPTE ST-2084, Hybrid Log Gamma, ACES or other workflow options where 16 bit has a significant advantage.
The illustration above shows the practical benefits of 16-bit capture and grading for HDR. Image A shows the original picture without grading while image B shows the waveform with the vertical axis in percent.
Image C shows an enlargement of two graded versions of image A: generic 10-bit on the left and 16-bit X-OCN on the right. These graded pictures reveal the substantial contrast, color and detail available in the highlight area of image A.
Image D displays the waveforms for image C, with the vertical axis in Nits from zero to 4,000. While the 16-bit version of image D shows smooth and continuous levels of gradation, the 10-bit version is visibly coarse. The waveforms are broken into discrete horizontal lines, which correspond to image banding. These artifacts do not appear when grading in 16 bit X-OCN.
As distribution channels migrate toward High Frame Rates, X-OCN is prepared. You can capture incredible 4K at up to 120 FPS, with no sacrifice in resolution, no line skipping. Need even more? O-XCN enables 2K capture at up to 240 FPS. That’s 10x super slow motion playback at 24p.
Instead of “baking in” your settings for Exposure Index, color space, LUTs, gamma, log and others, X-OCN captures these parameters as monitoring settings. This process is completely non-destructive, delivering the full potential of the original sensor data into postproduction. As a result, your colorist and editor are empowered with far greater decision-making flexibility than is possible with conventional video.
Smaller file sizes than RAW
At the heart of X-OCN is a unique algorithm, tuned for the F55 and F5 sensors. As a result, you get substantially smaller file sizes than typical RAW. This means longer recording times, faster transfer times, and post-production workflows that are far more cost-effective. The AXS-R7 delivers two modes of X-OCN recording in both 2K and 4K. X-OCN ST (Standard) is the choice for maximum quality while X-OCN LT (Light) is ideal where lower data rates and smaller file sizes are critical.
At the highest 4K picture quality, X-OCN ST has 40% longer recording time and roughly 30% shorter file transfer time than Sony RAW. The advantages for X-OCN LT are greater still: 136% longer recording time and roughly 59% shorter file transfer time.
|23.98 fps||240 Mbps||384 Mbps||389 Mbps||660 Mbps||943 Mbps|
|25 fps||250 Mbps||400 Mbps||406 Mbps||688 Mbps||983 Mbps|
|29.97 fps||300 Mbps||480 Mbps||486 Mbps||825 Mbps||1178 Mbps|
|50 fps||500 Mbps||-||811 Mbps||1376 Mbps||1966 Mbps|
|60 fps||600 Mbps||-||972 Mbps||1650 Mbps||2357 Mbps|
|120 fps||-||-||1944 Mbps||3300 Mbps||4714 Mbps|
The long loads you need
Sony understands the practical need for long recording times in the field. And the X-OCN system comes up big. Recording onto 1 TB cards, you can capture up to 168 minutes of content at the highest resolution (4K) and highest quality (ST mode). Of course, your recording times will vary by resolution, recording mode, card capacity and frame rate.
|Frame rate||1tb cards*
|512 GB Cards*
|256 GB card*
|4K X-OCN ST||24fps||168min.||84min.||42min.|
|120fps (f55 only)||32min. (s48 only)||16min. (s48 only)||n/a|
|4K X-OCN LT||24fps||284min.||142min.||71min.|
|120fps (f55 only)||112min.||27min.||13 min.|
|2K X-OCN ST||24fps||666min.||333min.||166min.|
|2K X-OCN LT||24fps||1012 min.||103 min.||51 min.|
|60fps||414 min.||207min.||103 min.|
Easy to work with
While some file structures can be complex, the X-OCN format interleaves audio and video in a single, simple file. This is the same MXF "Operational Pattern 1a" (OP1a) data structure that is well standardized throughout broadcast and production. Sony has used the MXF OP1a wrapper for several recording formats including the XAVC, Sony RAW, SR File and MPEG HD formats.
To establish broad industry support for X-OCN, Sony has distributed an updated Software Development Kit licensing program to an extensive list of third-party workflow vendors. And as of August 15, 2016, the very first compatible applications have started to appear. These include the following:
- DaVinci Resolve v12.5.1 or later
- FilmLight Baselight system v4.4.8489 or later
- OSD Colorfront system including Express Dailies, Transkoder, and On set Dailies 2016 or later
- Sony RAW Viewer v2.3 or later provides playback and trimming of X-OCN files based on imported EDLs.
Supports High Dynamic Range with active Nit display, ITU-R BT. 2020 (Rec. 2020), and ACES v1.0, exporting of
OpenEXR, DPX, ProRes (Mac® OS), and XAVC among many other features. RAW Viewer supports both
Windows® and Mac® OS.
We expect many more software announcements in the very near future.