[by Michael Grotticell, Broadcast Engineering]
Due to the laws of physics and geometry, scientists studying various demographics and how the human brain processes visual images suggest that Hollywood content creators need a better, academic understanding of the field of stereoscopic 3-D imagery in order to avoid making viewers uncomfortable. That was the general consensus from the recent 3-D conference on Stereoscopic 3-D for Media and Entertainment, presented in New York City by the Society of Motion Picture & Television Engineers (SMPTE).
Long story, short: Hollywood creatives and those that design content creation systems need to get together with “vision scientists.”
During the first day of the two-day gathering (SMPTE’s second annual), a number of technical yet revealing presentations by scientists in the field of vision imaging detailed where the biological, physiological and image sciences meet. A number of research studies conducted at the University of California-Berkeley, Newcastle University in the UK, York University in Canada, and Bangor University in Wales have been done to determine how people see and react to 3-D images. Virtually everyone was in agreement that more work needs to be done, including by their own community.
For example, it was revealed that a good understanding of geometry in motion imaging can result in the most effective 2-D-to-3-D conversions.
“[3-D] really can happen and be a fantastic medium,” said Martin Banks, lead vision science researcher at USC-Berkeley. He served as the chairman of the conference’s Stereoscopy and the Human Visual System sessions and gave a presentation entitled, “Focusing and Fixating on Stereoscopic Images: What We Know and What We Need to Know.”
“But we don’t know enough about how the human brain processes three-dimensional images,” Banks said. “Because the way brains process information is so different in different people, it’s not an easy thing to get your hands around. The more research we do in the lab, the more we realize the lack of ‘real-world’ testing that still needs to be done.”
Several of the scientists spoke about the need to test moving image footage, as opposed to controlled dot patterns in a laboratory, in order to spotlight which elements of geometry (depth cues) and color are most advantageous to human perception. Where humans focus their eyes, or “fixate” on a given scene was also discussed, as was “vergence accommodation conflicts,” which can lead to viewer discomfort and fatigue.
“About 30 percent of people cannot see stereo 3-D, due to specific binocular problems and reduced acuity,” said Jenny Read, of Newcastle University. “So, we wonder whether this medium is right for everyone, as the motion picture studios would like you to believe.”
Simon Watt, a researcher at Bangor University, suggested that the majority of major motion picture directors are over 45 years old, an age that is more conducive to 3-D viewing. This would mean that many of the effects that appear “normal” to them might not be so pleasing to younger or less experienced 3-D audiences.
The panel of scientists suggested that children’s brains are not fully developed enough to see 3-D clearly until they reach the age of eight to 10 years old. This would seem to confirm what various warnings in the press (and from manufacturers of 3-D technology like Nintendo) have stated about children viewing 3-D for long periods of time. Yet, despite all of the hype, no one can prove that 3-D is harmful to your health.
“Not enough research has been done to prove definitively the harmful effects [of 3-D] on human vision,” Watt said. “We do know that age is a significant factor in predicting the effect on brain sensitivity. For example, we have surmised that young people have more problems viewing 3-D than older ones.”
While the sessions were decidedly academic in nature, they could provide clues for cinematographers about what to do and not do when designing a 3-D frame. It was suggested that more light in a scene gives the illusion of more depth. It was also noted that higher frame rates, such as the 48fps workflow being employed by Peter Jackson during shooting of the next “Hobbit” feature in 3-D, produced less flicker and thus smoother 3-D sequences than the traditional 24fps most commonly used to shoot feature films. The real-world problem is that most theaters are not properly equipped to display 48fps (or higher) frame rates.
Howard Lukk, vice president of production technology for Walt Disney Studios (and SMPTE Technology committee chairman), said his company has conducted a number of tests that found people are more comfortable with slowly moving imagery in 3-D, as opposed to fast action.
Another engineer in the audience said that it takes at least three months to become adept at viewing 3-D images without discomfort or fatigue.
Joseph Flaherty, senior vice president of technology at the CBS Network and the unofficial “godfather” of HDTV — who helped shepherd the technology from the laboratory to the living room — said cinematographers and other creative people should consult with vision scientists and study their research, in order to get a better idea about what will work in on a 40ft movie screen or an HDTV set in the home.
“One thing that has concerned me about the current state of 3-D is the lack of understanding of the science of 3-D and how to make the technology work,” said Joseph Flaherty, senior vice president of technology at the CBS Network and the unofficial “godfather” of HDTV. “The problem is that we’re looking at this from a top down perspective instead from the bottom up. With HDTV, it took us more than 20 years to get the science right. Here [with 3-D] we’re starting with the screen and working backwards. That doesn’t seem right.”
In fact, as evidenced by the presence of the technical panels devoted to the subject, SMPTE has been working to foster better relationships with vision researchers. For their part, researchers like Bangor University’s Watt said he encourages feedback and input on his work.
“We as a scientific community want to understand mainstream media a lot better than we do,” he said. “Our research can make a contribution to entertainment and I think a better relationship with creative and technical people like the members of SMPTE can only help our work. It should work both ways.”