Originally Posted by imagic
"On a scene by scene (could be as short as a frame) basis, the projector analyzes the content and adjusts the luminance/iris/laser to provide the best possible image on the screen. To the extent that this changes the bottom black level or peak brightness level at that moment, the colors are remapped so as to remain “correct”"
"We apply the industry standard 2084 PQ curve – any ‘other curve’ would be changing the colorimetry from that authored by the content creator."
"Regarding “pay attention to all the metadata”, in the HDR10 standard, there are only two pieces of metadata which are often set incorrectly in a given piece of content. While other manufacturers have begun to use those data to set parameters within their projector, Sony analyzes the content and determines dynamically (to the original point of scene by scene tone mapping) the peak brightness and average brightness of that scene and tone maps the image based on the actual content."
Couple things wrong with this feedback. The first paragraph is talking about the dynamic dimming. If it was talking about something else, it would extremely easy to see adjustments in the luminance levels.
The second paragraph is misleading. There is no way you can follow PQ with a projector. If you followed PQ perfectly, you would clip. You have to have a point where you have your rolloff and you'd want to adjust that either shallow or extreme depending on how much signal there is (is the max 200 nits, 1000 nits, 4000 nits?). That would determine how much rolloff you need. You don't want to touch the first 100 nits, which is where the bulk of the information lies. But at the same time you want to have the ability to adjust the tone map so that you can compensate for the environment or viewing preference. Think of this as dynamic range control on a stereo. True high dynamic range audio is hard to listen to unless you are in a perfect environment. Try listening to a high dynamic range classical recording in a car on the freeway. You turn it WAY up for the quiet parts and then get blasted by the loud parts. If you follow PQ perfectly you HAVE to compromise the bottom to get the top, you only have so much range to work with. If you follow a perfect balance, it has to push the bottom DOWN, which makes most of the portion of video you watch DARKER. Sony doesn't allow you any control to change that balance so some titles will be too dark. This becomes more of a problem if the room has any ambient light to compete against or you end up with a screen that is big enough that total light output becomes an issue.
The third paragraph is also, in my opinion, false. Otherwise if you put up any ramp pattern with digital data, you would never see clipping at different contrast settings, because it would change the tone map to not clip. Even the opening sequence of "The Meg" will show you that they are not doing scene by scene tone mapping or they would NEVER clip. But you have to adjust Contrast HDR on a title by title basis or else you clearly get issues not only with image brightness, but also clipping. This barely takes any time with the projector and content to prove false, so I'm not sure why they would say it in the first place?? If they were truly doing any type of frame by frame tone mapping, you'd never have to adjust anything for any title at all, but it is blatantly obvious with such a minor amount of testing that this is far from the case??
The only thing Sony is doing dynamically is the laser dimming, and even this only applies to the first 3% of the image at most (from black to 3% APL). From there on it isn't doing anything at all.
At some point I'd like to have a sit down WITH a projector and content with their engineers. I am not sure if their marketing guys are just being mislead, or worse don't know, but to demonstrate these things is fairly simple in a room with the projector and content.