In my rush to get this out I made a mistake on one of the captions. The S-Log3 was shot at 3200ISO, not 1000ISO.
So here are some frame grabs from video shot today with my FS5. There is no image processing other than the grading of the S-log3 clip and the upscaling of the HD clips to UHD in the video.
Default factory settings or picture profiles were used. The footage was exported from Adobe Premiere CC using Media Encoder at 3840×2160, H264 at 75Mb/s for upload to YouTube and Vimeo. You should be able to download the UHD H264 file from Vimeo. This is what it looks like out of the box. All the shots were done at the same aperture (f9) and shutter speed (1/50) and the native ISO or 0dB gain used in each case. This means that the S-log3 was around 1.5 stops over exposed, which is about optimum for S-log and an 8 bit codec. As you can see the pictures are low noise with no significant artefacts and no banding in the sky, clouds or any other areas. You can also see that the S-log3 grades really nicely when shot this way and results in a very low noise image. In the video clip I have included some pans and tilts and everything looks perfectly normal to me.
Click on the thumbnails of the still images to go to larger and full resolution UHD and HD frame grabs.
Note that even though the S-log3 is 1.5 to 2 stops over exposed the cloud highlights are still well within range after grading. I could probably over exposed by a further stop and still had great looking highlights and even less noise. S-log really like being over exposed. Log is the exact opposite of standard gamma. With standard gamma you shoot protecting your highlights but with log you must shoot to protect your shadows.