Data requirements for the Sony A7s

Here are the recording options available in the Sony A7s:

Res. PAL NTSC Codec Data Rate Mbps Wrapper
1080p 24p, 25p, 50p 24p, 30p, 60p XAVC S 50 MP4
50p 60p AVCHD 28 MP4
25p, 50i 24p, 60i AVCHD 24 MP4
25p, 50i 24p, 60i AVCHD 17 MP4
720p 100p 120p XAVC S 50 MP4
1440x 1080 25p 30p MPEG-4 12 MP4
640x 480 25p 30p MPEG-4 3 MP4

To record internally, I would recommend XAVC-S. All three codecs are a variant of MPEG-4 AVC/H.264 family, though XAVC S is the easiest on your editing system. Within XAVC S, I recommend you always record at the highest data rate, which is 50 Mbps. No exceptions.

This is how the data rate would translate into hard drive space:

  • 375 MB/minute
  • About 23 GB/hour
  • A 16 GB card will hold about 40 minutes worth of footage in 1080p.
  • A 64 GB card will hold about 2.5 hours worth of XAVC S footage in 1080p.
  • A 1 TB drive will hold about 40 hours worth of footage in 1080p!

The memory cards supported are:

  • Memory Stick PRO Duo,
  • Memory Stick PRO-HG Duo,
  • Memory Stick XC-HG Duo,
  • SD memory card,
  • SDHC memory card (UHS-I compliant),
  • SDXC memory card (UHS-I compliant)

I recommend SDHC or SDXC cards, obviously Sandisk (specifically Sandisk Extreme Pro ). You don’t need any faster SD cards than already used by DSLRs, however, you need 64 GB SDXC cards for XAVC S. I recommend buying at least two, the second being the backup. Like me, if you’re shooting 25p and need to jump to 60p for slow motion, then buy three. One for PAL 25p, one for 60p (formatted separately in camera), and the third as backup.

The go-to codec to record the uncompressed signal is Prores HQ (4:2:2). 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

We’ll look at drives for editing in a later lesson. We’ll look at Prores solutions in the external recorders and workflows module.

What 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 that 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 A7s 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. However, this is mapped to various color spaces for each picture profile. E.g., if you select S-Log2, you must select S-Gamut color space. This is all done in camera, but you must select the right color space.

These extended color spaces are in full swing+super whites mode (0-109 IRE). If you work under a studio swing environment, then you must take this into consideration or risk clipping. When I spoke of some picture profiles being better for broadcast, this was specifically what I was referring to.

When grading, Sony recommends that you work in a 32-bit environment for maximum quality. We’ll look at this in the grading lesson.

Click on the link below to the next lesson or head over to the main menu (above). If you need help with something, feel free to send me an email. I’ll try to get back to you as soon as possible.