Thanks Sotti glad to see Chuckie responding to that.
This is exactly what I would have said prior to investigating a reasonable number of transfers.
I'm still seeing nothing in BD that makes me think mapping peak white to 235 is a bad idea and the numbers we are digging up do seem to bear this out. I am 99% certain that 235 is the way to go with BD.
I'm still not entirely sure about broadcast as I've said. I'm seeing more above 235 than with BD but I'm not yet convinced its enough to worry about.
There are times when I think "thats a bit clippy looking" but I usually find that disclosing through to 254 makes no visual difference in the whites to the end result. ie there was nothing up there anyway.
Now this is usually live studio footage I see it on the most , when I'm watching high quality drama or documentary : CSI , Seven Wonders of the Solar System ( which I worked on) I'm not seeing anything above 235 even when I'm sure its going to be there.
What I see is edge features ie ringing: The almost famous example shows this...most of the region above 235 does not make sense in terms of image content. For example the region on the car bonnet you would expect the centre of the flare to be the brightest point ,which it it is... until you get above 235 where the edges start to excurse for some odd reason ...doesn't make sense, certainly not in terms of photographic image content. To be honest it does smack of mastering error to me given the nature of the content above 235.
Its some sort of filtering issue where the edge detail is banging off the 235...ringing , bad interpolation, possibly even too crunchy a grade in that region.
I'll pick up "Seven Wonders of the Solar System" on BD and have a look. I know that our content on that was delivered as "video" level material
designed to be viewed with everything below 17 clipped to black and range up to 254. In fact I had to advise another team who were working PC level (entirely CGI shots) and then panicking about what happened to their blacks on a broadcast display.
Interestingly the cms we use on our workstations never clips at 16 or 235 it always shows some range below 16 and everything up to 254. I actually drop a secondary clamp in for the blacks for viewing purposes but the work is done with realisation for the necessity of range below 16 and range above 235. If I don't get that I'll knock the shot back. I do also check shots with a hard clip 16-235 and gamma variation to confirm robustness. However it is rare for us to be responsible for the final grade...my job is mainly to provide good looking match graded imagery that does what the client wants and is robust enough to stand up to additional color correction for the final grade.
(I've never had any video work rejected by the BBC or ITV but I have worked in places where it probably would have been if I hadn't highlighted some level problems...nasty clipped holes below 17 for example)
All broadcast displays I've seen show level all the way up to 254, some show a tiny amount below 16 but I'd say its probably a function of the CRT rather than a deliberate setting.
What I want to avoid is us going over the same old ground again with this thread. For example two camps forming , 235 camp saying that there is no useful level over 235, 254 camp saying that there is level over 235 so we should keep it and here are some papers that mention excursion.
Otherwise we will never get anywhere.
Johns WTWfinder is going to be very useful in this investigation.
What we should do is continue to analyse footage and once a reasonable selection of numbers are in we'll talk about what they mean and reach some sort of consensus...whatever that may be.
Lets not look for evidence that backs up one side or the other lets just get our own evidence and see what it tells us.
And by way of experimentation try running the alternative way on your displays for a bit and see what your observations are...its not going to kill you.