I've found some odd behaviour in the Release Build 15 with the histogram and traffic lights.
When I set the sensitivity to a lower than native setting such as ASA160, the histogram no longer runs up to, or off, the right hand side of the field. The traffic lights never light up no matter how blown out it gets. This behaviour is on both of the cameras that I tested for it.
The lens was wide open for this shot and the sky was completely blown out.
Back at a more normal setting of ASA320, if there is a trough in the light the traffic lights can go on and then off again even when the exposure goes further over. With the image below, I have two shots. The top one shows the LCD with the traffic light lit up showing that every channel is clipping- but when I openeed it up further for the bottom shot, the traffic light tells me that blue is no longer clipping... even though it is over exposed far worse than the upper shot.
I didn't get a picture of it but I managed to expose a harshly backlit image where at least 80% of the image was completely blown out and the traffic lights had come and gone completely so it was trying to tell me that not even 2% of the pixels were over in any channel.
It is obvious that it is wrong just looking at the image and at the settings but the histogram and the traffic lights were giving me the thumbs up.
I've experimented such problems with the traffic lights before the build 15.
When setting asa to 160, you might clip before 100. I have a test shot (shot at asa 100) where the highlights clip around 70 (and not 100).
A good argument I would say for leaving the ASA at 320.
IMHO we should really ask - again - for a pure CMOS RAW histogram and pure CMOS RAW overexposure ample.
This way we could use e.g. a 160 ASA setting for everybodies convenience, could even us the current histogram to check for the preview out "burn outs", but switch to the RAW histogram to be sure on what is actually recorded as footage.
From my point of view, the color and ASA of the preview is to make customers etc. satisfied, and for the DOP / AC when lighting needs to be adjusted. When actually shooting, a B/W view finder and pure RAW histogram and ample tells me much more of what I am doing, than any color "interpretation" and the according "interpreted histograms".
In fact we do not rely on the preset metadata we get from the RED ONE into RED CINE & Co. during post production. IMHO for many of us the big hype around RED ONE was EXACTLY to overcome those historical video approaches, but instead rely on what was on FILM earlier. And FILM means RAW now, not the 709 interpretation.
Anyone who agrees should add note here, so they hear us loud (if they hear anything due to NAB stress...)
Best wishes for a great show which I can't attend. I hope to see some good coverage from all you other guys and hopefully RED. I'd wish they would do some streaming from the booth, or at least add some downloadable recordings from their sessions.
Thanks listening :)
They are clearly based on the Rec709, as they change with your ASA settings. They got changed to log space, but thats it.
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