The Technology Summit on Cinema event kicked off with the above titled session. Ronan Boitard from Barco was first to speak. He is actually from the MTT Innovation team that has been working on a light steering projection technology, which Barco acquired about two years ago.
Boitard laid out the four options that he sees for next generation cinema:
- high contrast projector;
- dual-DMD projectors,
- direct view displays and
- light steering projectors.
High contrast (6000:1 to 8000:1) projectors are available today from the major suppliers. Dual-DMD refers to Dolby and IMAX implementations, while direct-view means LEDs screens, such as the CinemaScreen from Samsung and finally, their light steering technology.
What seemed to be clear over the course of the day was that high contrast and even dual-DMD projectors will only improve the dynamic range of cinemas so much (it lacks high specular potential). This category is Enhanced Dynamic Range (EDR). But cinemas need to get to an HDR solution, which direct view and light steering can do, Boitard thinks. However, he provided no details on how their light steering technology works.
To get to HDR, Boitrad sees four specifications that should be considered: peak luminance (must change); transfer function (current 2.6 gamma should change); color space (current XYZ encoding could change) and: quantization (12 bits not necessary).
He then presented the results of some studies Barco did that compared three transfer functions with XYZ encoding (gamma 2.6 with 1000 cd/m²; PQ with 1000 cd/m², PQ with 10K cd/m²) and 4 color spaces with PQ1000 (RGB Bt.2020, RGB ACES APO, ICtCp, YDuDv). His conclusions are shown below.
Getting the pixel representation is going to be critical to rolling out an HDR solution that can play well on the HDR (and maybe EDR) solutions coming to market. His paper may help to provide a framework for evaluating some of these key pixel representation decision points.
In questions after the presentation, Boitard was asked if tone mapping will be needed and acceptable in cinemas in the HDR era? He thinks it will be OK for slight differences in the capabilities of the display solution in the theater, but will the studios tolerate this? The display solution needs to be predictable and at least as good as what a consumer can get in their home. He thinks it will be 2-5 years before we see a true HDR cinema solution. – CC
