Other: S-Log more compressed DR than Rec709?

[alex1]

I was watching this video.

https://www.youtube.com/watch?v=U-HrXmRqpME&index=2&list=LLg469JLFi-XURh3hTXjiX9Q

And the guy explains that to get the 14 stops of DR the camera has to compress each stop a lot more heavily than say shooting a scene with only 6 stops of DR.

Is this true or partially true? I've never heard of this before.

 

[starcentral]

yes it is 100% true on a technical basis but sounds a bit like trick question.

Look at this curve and you can see that as the scene reflectance increases from 0 to 1600% the mapped IRE becomes more and more squeezed together the closer you get to the top end of the IRE scale.

But what does it mean in real life and should you be concerned about it?

If you shoot a 6 stop scene on a 14 stop camera, in slog mode at least, the camera is still going to map those 14 stops across the entire 0-109% IRE scale so nothing is gained and nothing is lost. ie. you'll end up with the same amount of data represented for each stop whether you shot a 6 stop scene or 14 stop scene.

But where you decide to PLACE those 6 stops can have some degree of benefit or not. Refer to the opener on this thread on data distribution to get an idea of what I mean. http://www.dvxuser.com/V6/showthrea...etween-12-bit-RAW-16-bit-RAW-amp-10-bit-S-Log

Now if you shoot a 6-7 stop scene using a cinegamma REC709 curve which is around 7-8 stop anyways you will get more data per stop but you probably won't need it if you shot WYSIWYG anyway.

Make sense?