Originally Posted by JonStatt
You are right, that a clever DI implementation will "play" with the gamma to do exactly what you said. But by definition if you clamp the iris, limiting light output by 10 times, you will also be cropping substantially the peak white achievable. So for mid shades, you can push them back up. But for upper shades, you will hit the limiter and you won't be able to get those sparkly bright stars or skyscraper lights. As you noted, you will also create clipping. That's why I said aiming for a 10 fold increase in contrast is playing a numbers game. 3 or 4 times is much more likely to be the limit of a good implementation. This is still very worthwhile, and I am not poo-pooing this feature at all. Quite the opposite, and I am looking forward to seeing how well the JVCs perform with a real-world usable setting.
Right, so a DI would actually reap the most benefits in low APL scenes, which are supposed to be very dark, but the "brighter" parts of the image are nowhere near peak white level, so there's a bunch of room to push them via gamma without clipping. (If I get all this correctly).
Since I've been considering both the new Sony 4K or the new JVCs ("more brightness...deeper black level...which do I want?) I've been playing again with brightness on my JVC RS55, also putting it into high bulb mode which I normally never do. Pumping up the brightness actually "helps" many dark scenes, night city shots, spaceships in space etc like the first shot of the Prometheus ship, but making bright areas that much more solid and vivid. Stars sparkle more realistically, etc, but the black level doesn't rise as perceptibly. With a DI, as you keep pointing out, to the extent it clamps down for the darker blacks, you'd loose the gains you get with higher brightness even in dark scenes.
But then for some movies I lower the brightness a lot strictly to get visibly better black levels and THAT too really adds richness and believability in it's own way. Unfortunately only increases in Native Contrast will give us both.
I was wondering if the switch to native 4K resolution would actually make it harder for LCOS to maintain or increase native contrast, but it doesn't seem to be the case. JVC reduced it's pixel grid spacing this year - which someone pointed out likely helps them prepare for the next native 4K chips - and they boast gains in native contrast.
Next year will certainly be interesting. I wonder if, seeing that a major benefit of 4K is increasing screen size, it's possible JVC will add some flagship native 4K projector with substantially greater brightness a la Sony.