Here's the S-log2 formula. Knock yourself out.

https://github.com/ampas/aces-dev/blob/master/transforms/ctl/idt/vendorSupplied/sony/F65-F55/idt-SonyF65-F55-10i_Daylight.ctl

@Trackzillas, like you I am very excited about the cam but I don't think we'll see 15.3 stops in video unless we can get a Cinema DNG hack or Sony opens it up somehow. So the guys correcting you are possibly right. But I am with you bro! This cam kicks some serious behind whatever it ends up being. ( pssst. . . truth is we still don't know ).

Whatever the dynamic range is in S-log2 I am convinced that it will mitigate most highlight retention complaints so common with us 'video snobs'. Man video and audio pros are so hard to please. I work in pro audio as well and folk are just plain finnicky about the tiniest details. The funny thing is that the end users rarely care whether you used a £50 000 fairchild compressor or a plugin! If you are a prosumer and are still looking for more in a camera before you dive in your expectations may need a bit of a rethink. You may need to wait another year or two to get your 10 bit or better RS performance. Or get a higher model of course. This camera is incredible whatever its rating in video. Our crappy old DSLRS and mirrorless cams give us about 8 or 9 stops if we are lucky. We just jumped to maybe about 14 and folks are acting like we need to calm down.WOW! Shout it from the rooftops man!!!! What's up with all this cynicism?This is a liberating tool. If it gives us even one stop lower than raw you realise that puts it in super high end territory as far as dynamic range goes?

Lets not forget the best use for that super sensitive RAW at 15.3 stops of dynamic range is timelapse. And with an electronic shutter mode it does no damage to the mechanical shutter. There will be time lapses that make you want to get a 4k screen. I watched the Samsung UHDTV curved screen in a hifi shop on the weekend. I can see why 4k is special now. I have been sitting on the fence about 4k as I always felt true HD was great but nature, timelapse and sport looked just spectacular in 4k. And I mean amazing! However - all the trailers with CGI looked liked computer games though and I think dramas would have to be filmed well but man did it leave a lasting impression. But the timelapse stuff was insane - filmed with lesser cameras I might add.

Once you see what the fuss is about, you get excited and creative juices start to flow - you start picturing certain types of shoots. Perhaps with a keylight behind the talent in a dark tunnel. Maybe lit by the moon, how about shooting a little after the golden hour - it becomes the golden four hours now LOL. One doesn't expect too much complaining or cynicism in the face of the technical achievements this camera brings. I think most of us here are artists not scientists or techs. There is always better and superior in this game and at the end of the day affordability rules the roost. I have waited for ten years for this camera so excuse my excitement. Like trackzillas, I am a singer and this camera will allow me to do my own shoots and if I shoot properly - will get broadcast ready results. It is the first broadcast ready camera I can afford. To me that is huge. In the past I was looking at twice the price for less performance. I have currently saved 1k of the price of entry. By July thousands of folk around the world will be shooting with one the most empowering cameras the world has ever seen for $2500. If you ask me - I think that is bonkers! Let no one dampen your enthusiasm bro.....this cam will deliver

@TrackZillas I believe (my interpretation) Den was giving his impression not scientific tested fact that the camera had the same DR as the F5. I could be wrong. Also which mode from the F5? The F5 is also not 8bit which matters jamming that much DR into a codec. Look at Slog 2 in the FS700 it looks terrible and ultra noisy with the internal codec.

In the end we don't know which is why I really want to see more tests. The camera is under a month from release and we haven't seen anything other than extreme low light tests. I get it the camera shoots amazing low light but I want to see the image in not so extreme situations that most of us would shoot in regularly.

This is completely unscientific, but if you watch the behind the scenes video from Den's "Arbroath Smokies" video you can make a somewhat visual comparison of the Sony A7s and a Sony F5 shooting in the same location and under similar conditions. The behind the scenes video was shot with a Sony F5 (according to Den's comment on the page) and the "Arbroath Smokies" video was shot with the A7s slog2 at 1080p internally. There are several scenes from the "Arbroath Smokies" video intercut in the behind the scenes video:

Of course we are not sure how the images from both camera were post processed, so once again it is completely unscientific.

@TrackZillas

I hope it does I really do and Den does great work. The skeptic in me wants to see footage by someone who wasn't hired by sony to make a promotional video. I don't think Den is going to say anything negative about the camera. I'm still probably going to be buying one as it checks a lot of boxes but the lack of much other than low light tests has me holding off on pre-ordering.

Maybe we should wait until Photokina and see what else is coming up.

Sony A7S Video Demo (S-Log2 gamma) 20 seconds

A review with some jpg samples to download:

http://www.dcfever.com/news/readnews.php?id=10796

"Should be noted that the use of S-Log2 when shooting, the lowest ISO sensitivity of ISO 1600"

The dynamic range on this camera is superb, amazing highlight recovery.