Originally Posted by Javs
The bolded is the reason I am going to try the curves.
You are correct about everything else. We agree. In fact, with my two comparison photos, I didnt touch the camera exposure, so you can actually see (And those shots were literally out of the box) that most of the brightness levels are matching except for the highlights, which it to be expected. So yes I would be watching most content at 15fl you are right except for highlights, but I then asked myself, why would I go to high lamp or wide open iris, and throw 60-70k contrast in the bin, when it looks pretty close already? DI or not.
BTW I can get 130 nits easily now with my new projector. But I would likely reduce to 100 just to gain back some contrast.
There is no need to use high lamp in HDR if you can get more than 100nits in low lamp. I get 135+nits in low lamp, so I'm happy to use this.
You don't have to throw any contrast away if you get a linker and use the DI in HDR.
You seem to be obsessed with on/off contrast, but it's not the only parameter for a good picture (as long as the black floor isn't too high or low APL scenes don't look grey, which is solved with the DI).
With the iris fully open, you do lose some native on/off contrast (I still have more than 45000:1 though so it's not that bad) but you get more ANSI contrast, which I would argue is MORE important for HDR. You also have to realise that what matters is perceived contrast and perceived black, not absolute contrast and absolute black. With a brighter picture, your pupil is more open so a raised black floor looks black as long as you don't come from a low APL scene. If you come from a low APL scene, your pupil isn't as dilated so the raised black looks grey and that used to be a problem especially in fade to black, but it's not anymore with the DI. With the DI, you get great dynamic on/off, great black floor and great ANSI contrast. It's a win-win!
For example, watch the end credits of Trolls, you'll be amazed at how black the blacks look and how colorful it looks in HDR, despite the iris being fully open. Absolute black is raised, but perceived black looks blacker than black. Honestly the HDR picture, well calibrated, is mesmerizing. I've just watched some of Lucy, there is no comparison with the bluray or the UHD Bluray in SDR BT2020. The HDR picture is really in another league altogether.
The main reason for not going SDR BT2020 is simply because that's not the way the content was mastered. Yes, it was great before we got the ability to make these custom curves and to get the DI back, but now it's simply the wrong way to look at UHD Bluray. Where do you set the slider on the player for 4000nits titles? So that it doesn't clip the highlights but gives you a dim picture, or so that the picture is bright enough at the expense of resolving details?
If you want accuracy and don't care about immersive sound, absolutely, go for bluray, but if you want immersive sound it's UHD Bluray, at least for a while. And now it looks very, very good.
If I had been able to choose at the time, I would have asked for 1080p SDR 4:4:4 12bits DCI-P3 with the least possible compression. I would have been very happy to upscale this and get a fantastic picture. But that's not what we got, and we have to do our best to reproduce the content in the best possible way.
Until we were able to get a good HDR curve, it was with SDR BT2020 because that was the least damaging way to do so. But now, really, there is no reason to convert the content in an approximative way and be happy with that.
I've been very unhappy with HDR until quite recently. Now, I'm very happy with what I see, and I wouldn't go back.