In Part Four we looked at filters and internal recording modes. In this part, we’ll look at external recording as well as the entire data wrangling workflow for the Sony a7R II.

Atomos Shogun

External Recording

The Sony a7R II, like the a7S, outputs ‘clean’ 4K via HDMI (Micro Type-D connector). Here are the specifications:

Resolution 2160p 1080p
PAL 25p 25p, 50i, 50p
NTSC 24p, 30p 24p, 60i, 60p
Codec Uncompressed Uncompressed
Data Rate MB/s 500 250
Wrapper HDMI 2.0 Baseband Protocol
Color Space x.v.Color (xvYCC)
Gamma Rec. 709, S-Log2, others
Bit Depth 8-bit
Chroma Subsampling 4:2:2

What in the world is x.v.Color or xvYCC?

xvYCC or x.v.Color (same thing) is a proprietary color space developed by Sony that has the following characteristics:

  • Similar to Rec. 709 so it can be displayed on current broadcast systems, however –
  • It has an extended range that goes beyond studio swing. Rec.709 displays 55% of the Munsell colors whereas xvYCC can display 100% of the colors.
  • Sony 4K Blu-ray disks will support xvYCC.
  • Most modern GPUs already support xvYCC.
  • Already an official part of the HDMI protocol.

 
Just to be clear:

  • In stills mode, the Sony a7R II shoots in sRGB mode (with sYCC gamut a.k.a the sensor gamut) or AdobeRGB mode.
  • In video mode, it shoots HD as well as UHD in xvYCC mode. Both are full swing.

 
Whether you’re working with 1080p or 4K, you must take care in your color transformations while working in xvYCC mode. If you work under a studio swing environment, then you must take this into consideration or risk clipping.

When grading, Sony recommends that you work in a 32-bit environment for maximum quality.

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What is S-Log2?

S-Log2 is a gamma curve that keeps the image flat for grading. If you plan on using S-Log2 with the a7R II, test the camera using the same system used in this video:

The two major changes are:

  • Base ISO is 800 on the a7R II, while it’s 3200 on the a7S.
  • The noise characteristics at various ISOs might change, so don’t just follow the video as-is.
  • The color and gamma (S-Log2) will vary slightly from the a7S. Don’t expect it to match in its default state.

 
S-Log2 is not the only gamma available. Here are the others:

  • Movie
  • Still
  • Cine1-4 – these are possibly Cinegammas, from 1 to 4. This is roughly 460%.
  • ITU709 – this is Rec. 709
  • ITU709 [800%] – this is probably Hypergamma. It offers more range than Rec. 709 and Cinegamma but less than S-Log2

 
Various gammas respond differently to grading, which you MUST do if shooting in any gamma other than Rec. 709. E.g., I prefer the way S-Log2 grades over S-Log3. Others might prefer a different gamma. That’s why it’s all there, and you get to test and choose the one you like the most.

Other settings in the Sony a7R II

Gamma is an important way to manipulate the image. Here are other ways:

Picture Profiles (7 options) Black level, Gamma, Black Gamma, Knee, Color Mode, Color Level, Color Phase, Color Depth, Detail
Creative Styles Standard, Vivid, Neutral, Clear, Deep, Light, Portrait, Landscape, Sunset, Night Scene, Autumn Leaves, Black & White, Sepia (Contrast -3 to +3 steps, Saturation -3 to +3 steps, Sharpness -3 to +3 steps)
Picture Effects Posterization (Color, B/W), Pop Color, Retro Photo, Partial Color (R, G, B, Y), High Contrast Monochrome, Toy Camera, Soft Focus, Soft High-key, HDR Painting, Rich-tone Monochrome, Miniature, Watercolor, Illustration
White Balance Auto WB / Daylight / Shade / Cloudy / Incandescent / Fluorescent (Warm White / Cool White / Day White / Daylight) / Flash / Color Temperature (2500 to 9900K) & Color Filter* (G7 to M7: 15 steps, A7 to B7: 15 steps) / Custom / Underwater
Noise Reduction High ISO NR: Normal/Low/Off selectable
Lens Compensation** Peripheral shading, chromatic aberration, distortion

Notes:

  • *This allows you to add ‘tints’ by changing the colors in minute increments
  • **Only for Sony-approved lenses.

 
Mere mortals have spent years with their Sony cameras without knowing about all the styles provided. However, it would be wise to test all of them thoroughly. The combination of the above is what makes a ‘secret sauce’ for each cameraman.

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How to get maximum video quality from the Sony a7R II

It’s simple really. Based on what I know so far (which could change!), here’s where I would start for maximum image quality for the Sony a7R II:

  • Shoot at ISO 800
  • If you go beyond f/8 diffraction kicks in, reducing resolution. Optimal aperture (theoretically) is about f/5.6 for maximum sharpness.
  • Gamma – S-Log2, default settings, and don’t touch any other profile setting. If I had to change, I’ll reduce the sharpness to its lowest setting.
  • Follow the wolfcrow system for exposure.
  • High ISO Noise Reduction: Off
  • White Balance: Custom (2500 to 9900K)
  • Manual mode and manual exposure
  • Lens compensation on for Sony lenses; off for everything else.

 

External Recorders and Monitors for the Sony a7R II

There are four decent external recorders for the Sony a7R II:

 
You can use other recorders that take the HDMI signal, but are not recommended for field use. Which is the best size for 4K? I prefer a minimum of 7″.

Right now, the recorder that most interests me is the Video Devices PIX-E, though I own the Shogun. To know how the Shogun compares to the Odyssey 7Q+, check out my article here (it’s a little old, and newer updates have come from both parties). Here’s my review of the Atomos Shogun:

One ‘scary’ prospect about HDMI is that the cable connector really does not lock in. Sony provides a cable lock and it works surprisingly well, as long as you don’t have to take it on and off often. I prefer using a lock that comes with a cage, though there aren’t many cages out at the time of this writing. For reference, here’s my Movcam cage review for the a7S:

For PL-mounted lenses, I also recommend the Lock Circle Birdcage.

The go-to codec to record the uncompressed signal is Prores HQ (4:2:2) or Prores 4444 (PC users can use DNxHR/HD as long as the codec is supported by their NLE). At 422 it will have a maximum data rate of 880 Mbps (110 MB/s), though real-world data rates will be lower based on the frame rate and content. This is how it translates to drive space:

  • 6.6 GB/min
  • 396 GB/hour
  • A 120 GB SSD drive will hold about 18 minutes of 4K footage
  • A 1TB SSD drive will hold about 3 hours

 
This data rate will be hard on your computers, so you’ll need fast drives for on-set copying and duplication. A 7,200 rpm drive should be able to sustain about 110 MB/s so you should get real-time copying. Playback would definitely demand a slightly better drive or SSD or RAID solution. I would only grade in a 32-bit environment to avoid problems with banding and posterization due to the 8-bit codec.

I would use LUTs only as a reference, as explained in the video above.

Even though the spec is HDMI 2.0, the signal is plain-old HDMI 1.4 (limited to 30p), so you can use those monitors that accept a UHD signal.

To connect the recorder or monitor, the weapon of choice is the Hot-shoe Monitor Mount (from $5 to way more):

hot shoe monitor mount

In Part Six, we’ll look at batteries, power and audio for the Sony a7R II.

 

2 replies on “Sony a7R II 4K Preliminary Guide (Part Five): External Recording and Data Wrangling”

  1. i viewed numeral contents on the net lots of expert gudes are available for wanna be indi filmmakers and photographers, i make it a point to read wolfcrow  it has lots of expert advise.. Thank you … and very Few Indian filmmakers online….

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