Tuesday, 29 September 2015

A Gleam In The Actor's Eyes: Pixar Supervising Technical Director, Rick Sayre on HDR

IBC Executive p30

http://issuu.com/newbayeurope/docs/ibc2015_executive_summary/30

Attending computer graphic show Siggraph in 1985, Rick Sayre first came across a small outfit called Pixar. It was showing the Pixar Image Computer, a machine born at LucasFilm that had the computational power to manipulate digital images with high resolution. Impressively it was able to handle 12-bit colour values, over and above the 8-bit depth which has been common for much of content production ever since. Moreover, these 12-bit colour components could represent values greater than 1.0.

“I was encouraged in the very early days of Pixar that the people there had total respect for the imaging process,” says Sayre, who joined the start-up in 1987 and has been involved in many of their short and feature projects from Toy Story onwards.

For most of the past thirty years in CGI and VFX it was only possible to display a limited range of light values for images,” says Sayre. “By convention we picked 1.0 for the brightest value we could make, and accepted that 0.0 wasn’t really black. Now, with the new high dynamic range displays, we can begin to talk about images as a photographer would - in terms of contrast, mid greys and tonal structure. Not only VFX elements and light probes, but finally the images the audience will see can move beyond that 0 to 1 range.”

Sayre was involved in Pixar's pioneering work in creating an HDR finish for Inside Out and was Digital Imaging Consultant on the Dolby Vision HDR for Disney's Tomorrowland.

Unlike the current migration to 4K and Ultra HD, the addition of HDR does not incur a huge knock-on cost in data handling. “Improving the pixel has a much lower incremental cost than making more of them,” he observes. “More pixels cost more to render but better pixels require more care.”

HDR manifests itself clearly in the brightest areas of a frame such as metallic reflections or light sources. Sayre says that on Tomorrowland, the technique “revealed a gleam in the eyes of the actors which it has not been possible to show theatrically before.

"We have yet to fully explore what it means to not only capture in HDR but to light for HDR,” he suggests. “A DP will know instinctively what an audience is going to see and what dynamic range is appropriate. Today, you might gel a window on location interiors to avoid it looking blown out. With HDR capture you don't necessarily have to do that since you can delay the decision until post. So now you can show the audience what is outside that window. The question is whether you should, in terms of the story. The DP needs to be involved in that post production process. We need to beware of gimmicks.”

In addition, HDR between scenes will need consideration. “Moving from a night time interior straight to a daylight exterior may require a few frames of adjustment, depending on how we wish the audience to experience that change. Making HDR practical for editorial is another important step.”

Sayre's inspiration outside of the film industry come from photography and the natural world. “We are hard-wired to appreciate the beauty of the forms we see around us and as revealed in our understanding of physics.”

He views the advent of virtual reality as a fresh approach to a style of storytelling that harks back to the ancient Greek theatre-in-the-round.

Many of the storytelling dilemmas we are struggling with right now were present thousands of years ago with ideas of audience interaction and breaking the fourth wall,” he suggests.

The veteran employee has seen the company grow into the world's leading CG animation house under the auspices of Disney which acquired Pixar from majority stakeholder Steve Jobs in 2006.

When I started here, you could fit the entire company in one room, and everyone knew everyone,” says Sayre. “Pixar was small, intense, free-wheeling and idealistic.”

And his favourite Pixar film? “That's easy, The Incredibles.”







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