Originally Posted by odyssey Darin,I don’t think that Wolfgang meant that a reflective room makes increases in sequential CR completely irrelevant. I think what he meant is that the more reflective the room, the less important higher sequential CR becomes. In other words, you have to go lower in APL or some other indicator of a dark image before the benefit of increased sequential contrast becomes meaningful. Ultimately, you would have to go to a complete blackout before you notice it. Obviously, the reflectivity of the room does not change the sequential CR measurement. However, the only significance of sequential CR is that it’s a proxy for image contrast, especially low APL image contrast, and the room obviously changes that.
It is true that no matter how much on/off CR you have, low ANSI CR can kill your CR in mixed scenes and the light room is about killing ANSI CR (unless you have other lighting). So, the crossover point where on/off CR matters more moves down (toward darker). But, over 2k:1 would still matter in some mixed scenes even in a white room, just less of them from low ANSI CR (either from the projector or from the room). For instance, using this calculator here:http://www.cinemablend.com/new.php?id=8853
to estimate different simultaneous CRs, if I use 100k:1 on/off, 500:1 ANSI, and 2.5 gamma with projector A, while using 2k:1 on/off, 500:1 ANSI, and 2.5 gamma with projector B, and use a high .1 for room reflections, then for a 10%stim/0%stim checkerboard that estimates 19:1 simultaneous CR for projector A and 8.7:1 simultaneous CR for projector B. I could use a 2.2 gamma for projector B to get 10.5:1 simultaneous CR there. In both case the 5%/0% checkerboard has over 3x the simultaneous CR with projector A as B, even in what would have to be a pretty light walled room for .1 reflections. That is enough reflections to take the ANSI CR down to about 20:1, even though the projectors could do 500:1.
I have little doubt that if the same projector was setup with either 100k:1 native on/off CR or 2k:1 native on/off CR and all else was equal, while done in a white room, pretty much anybody here who understands video much at all would be able to see the visible difference that 100k:1 would bring, after being shown various material. TI can't get there now as far as I know, but a 4 panel system could get pretty close and exceed 100k:1 overall (where native vs dynamic blurs some as there is smaller native in small zones).
Originally Posted by odyssey Regarding increased sequential CR for DCI projectors, there is very little interest in pursuing it. The two main reasons are the ambient safety light limitation and the need to optimize light output.
Somebody else posted that there is work being done on a liquid iris with multiple rings where each ring can be charged to make it dark. I thought he said that was for DCI. The ambient safety light limitation is an issue outside of homes, but from what I've seen it sure looks to my eyes like there are theaters where the DLP projector looks like it is by far the limiting factor for on/off CR. I don't believe that the lighting I've looked at in at least one theater while viewing a movie was coming even close to lighting up the screen as much as it was lit up on blackouts. There is a new theater around here with lots of lighting and in that case it might be lighting up the screen that much. Watching The Ruins
was pretty pitiful with the whole theater pretty much lit up. Basically ruined parts of it IMO. A friend and I had just come from being disappointed with about 6k:1 dynamic from one projector in his theater since it didn't do as well with dark stuff as an RS2, but that 6k:1 killed the experience we got in that theater with the 2k DLP as far as how realistic the dark scenes looked. That may be the last time I go to see a dark movie at that theater.