What's the difference btw. Cinegamma and S-Log?

[Gene Sung]

Just curious, but what is the difference between the upcoming Cinegammas on the FS700 vs. something like S-Log which is available on the more expensive Sony Cameras?

Aren't they both just flat-ish picture profiles? What makes the S-Log more special? Is it because the S-Log is a 10 bit profile? But what about when the FS700 4K recorder comes out and then the camera becomes 12 bit? Can the FS700 then use the higher end profiles?

 

[FelixGER]

I think cinegamma is still a gamma curve that alters and shapes the data the sensor sees. That´s why there are 4 differen cinegammas for different situations.
S-Log must be nearer to the RAW sensor data with all information in it.

 

[nyvz]

Actually S-log is further from RAW in that it is a stronger gamma curve applied to data off the sensor which is normally linear light

It is only nearer to RAW in many cases in the sense that most manufacturers implement log gamma curves in such a way as to contain all of the range coming from the sensor as opposed to their other curves which throw away dynamic range. Log is also a bit more efficient for containing light information since light is logarithmic itself even if an image sensor is linear. Many manufacturers (Canon, Sony, etc) tend to cripple their non-log gamma curves by throwing out highlights and sometimes shadows to give a contrasty image that may seem more compatible with standard broadcast curves. Frankly I'd rather be able to shoot pleasing images in camera (not Slog) that also still use the whole range of the sensor. S-log is awfully post-dependent and I wouldn't want to get screwed in post by a production/editor/colorist not knowing how to properly handle log (or log-ish) images.

In the case of the F3, my understanding is that if you use the built in cinegammas instead of slog or other 800% gamma (that is part of the s-log "upgrade"), you are throwing away about 2 stops of highlights, just clipping them right off.