SMPTE’s Technology Summit for Cinema (TSC), held at NAB, was a huge success this year. With 500 seats in the auditorium, it was a full house for nearly every session held during the two days of conference. The two most memorable sessions were those on laser projection, and on higher frame rates. Equally notable was the keynote speech given by Chris McGurk. And a session on second screen in the cinema also deserves mention.
Sony demonstrated its laser projector, producing 7.5 ft-L through RealD 3-D glasses on a 2.4 gain silver screen. Arguably, the convention center auditorium in which TSC was held was not a match for the Coliseum at Caesar’s Palace, and the Sony demonstration deserves more scrutiny in a better environment. Somehow, contrast and color weren’t as sharp as expected, and it could have been an artifact of the viewing environment.
More impressive were the numbers. Sony is using a laser illuminator produced by Laser Light Engines. Bill Beck, founder of the company, described the illuminator as having 100x the lifetime of a xenon bulb. The illuminator is able to provide some 25,000 to 50,000 operating hours at 30% to 50% less power, while also reducing the HVAC load. Laser Light Engines may not be quoted as the provider of every laser illuminator now being shown on the market, but it appears to have IP in every design. LLE perfected the reduction of green speckle, an artifact that occurs with coherent light. Reflections of the light off a surface will cause erratic cancellations and additions, creating a speckle pattern. LLE reduces this anomaly by modulating the frequency of the laser.
Laser light regulations, however, remain a significant hurdle. Casey Stack of Laser Compliance points out that laser light passes through similar homogenizing optics to that of xenon light, such that it’s not possible for random laser beams to bounce around. But overcoming the political aspect of laser light regulation requires time.
Marty Banks, Professor of Optometry and Vision Science at UC Berkeley, presented a compelling way to predict visual comfort with 3-D imagery, taking into account temporal and spatial disparity errors. Higher frames and the display of left-right images in the same temporal relationship that they are captured in are best. Triple flash introduces more motion artifacts, but less flicker artifacts. However, when flashing images, the doubling of frame rates will reduce spatial errors by 50%. All of which means put on your 3-D glasses when the movie screen tells you to do so, and enjoy the show. (As best you can.)
Siegfried Fößel of Fraunhofer discussed the concept of shooting at very high frame rates at a wide shutter angle and combining frames to produce lower frame rates with smaller shutter angles. This is the same concept as Doug Trumbull has been touting, but interestingly, Fraunhofer is not as happy with its results. Steve Long, with the US Department of Defense, who has long been interested in digital cinema, reported tests run by the government to learn at which frame rate a knee occurs beyond which human vision perceives limited improvement. His number was 54 fps. Doug Trumbull quoted from his studies, complete with subjects measured by electrocardiographs and electroencephalographs, determining that 72 fps was the magic number. TI projectors are limited to 60 fps per eye, which fortunately sits in the middle.
The session that stepped into Neverland, however, was about “second screen.” Originally conceived as a session to discuss the trend of second screens in the home, it branched out to discuss the potential of second screen in the cinema. Missing was a much needed quote from Steve Jobs: “You go to your TV when you want to turn off your brain. You go to your computer when you want to turn your brain on. Those are not the same thing.” Substitute cinema for TV, and the quote is equally valid. It’s why content designed to bridge the big screen with handheld devices – such as voting on an ending – should remain in the engineer’s cubicle.
Which is also why it was useful to have Chris McGurk as a keynote for the event. As Chris describes himself, he’s a distributor, not a technologist. He’s exploring a narrowcast and programmatic model for distributing independent content into cinemas. Notably, the model he described puts technology to work in ways that systems today may not be designed to support. Which should give the engineers food for thought.