Is the LK970 not an HDR projector? Is it SDR? Whats the difference. Is native 4k HDR? And true 4k like the LK970, SDR? I actually dont know what either of them even mean.
I will say that HDR is a term that really - REALLY - bugs me.
HDR was used in photography to begin with. It was used to deal with the limited dynamic range of digital cameras. You could shoot a 'balanced' image of a scene that had bright areas and dark areas and the dark areas would be too dark, and the bright areas would be too bright, and there was no way to correct it. Someone then got the idea to overexpose the picture, so you could get more detail from the dark areas, then underexpose the bright areas to get more detail from them. Then, combine the three images to get good details across the board from dark scenes to bright scenes and that is what HDR truly is when applied to photography.
HDR for video viewing means something completely different. It seems to be a remapping of colors to make 'white' much brighter than it used to be. So, that when you capture an image of the sun, and show it as 'white' on your TV, it is almost blindingly bright. In the old days, with standard dynamic range, the sun would just appear 'white'. There was nothing that was blinding about it. But, newer TVs which have high dynamic range, are supposed to put 2,000+ nits on screen, when needed, which will almost make you look away from your TV when you see specular highlights, like the sun, or a sunlight reflection off of something. Which means 'white' is not just white, but it is an intensity of white. It changes the dynamic range of the TV and the tone mapping to the TV itself from previous standards to the new high dynamic range standard.
Why they needed to come out with multiple versions of HDR tone mapping is completely beyond me.
Projectors are pretty much incapable of truly delivering HDR. They just don't get bright enough. You would need several thousand lumens on a 100" screen to get acceptable HDR. But, the added tonality of HDR content is supposed to be pretty good no matter what and the added colors of HDR content is really what makes it shine. So, you can view HDR content and get the added color depth it offers on a projector and see some benefit from it.
I'm not entirely sold on HDR yet as my post should indicate, but in fairness, I think I need to do more viewing of SDR Blu-rays and compare them to their HDR counterparts on my projector and then do the same on a good 4K TV.
EDIT: Looking for a bit on YouTube, this was the most technical explanation of HDR and what it is supposed to be. I didn't see much definition of why HDR has different standards (HDR10, Dolby Vision), but I do get that remapping the brightness level matters because a white piece of paper shouldn't be as bright as the sun, and right now, with SDR, that's how things look. With HDR, paper needs to just be 'white', while the sun should be 'blinding white'. So, a display needs to remap that brightness.
But, HDR seems to be more about the display being able to have much more contrast within the display at any time. Apparently REC2100 defines that as a 200,000:1 contrast ratio.
