3D Nausea Easily Preventable, Sony Pictures Guru Says

LONDON -- Confirmed accounts of people getting sick from watching modern 3D images are fewer and farther between than media reports suggest, and the occasional cases could be prevented by producers and directors avoiding common traps, Buzz Hays of the Sony 3D Technology Center on the Sony Pictures Studios lot in Culver City, Calif., said at a briefing last week.

Hays demonstrated the mistakes that can give viewers headaches and nausea by screening a static test shot to show how extreme depth makes the viewer’s eyes diverge -- look out and sideways -- instead of making them converge normally, or look inward. “I warn you this will hurt like heck,” Hays said before screening the test, which showed objects at wildly different depths apart. “Producers make the cardinal mistake of falling in love with the image on a monitor,” Hays said. “Then when it’s shown on a large screen, viewers’ eyes diverge."

A common myth is that “you can’t do fast cuts in 3D,” Hays said. “That’s wrong. There is a problem with fast cutting if the shots show different depths and the eye’s convergence keeps changing. But if you smooth out the depth differences between shots it’s much easier to watch fast cuts. And you can adjust convergence at the post-production stage."

But other problems can’t be “fixed in post,” Hays warned. “If the camera lenses are too close” and spaced apart “much less than the human adult inter-ocular spacing of 63.5 millimeters, like the eyes of a mouse, everything looks too big,” he said. “That can’t be fixed in post. If the lenses are too far apart -- with, say, 100-millimeter interaxial spacing, like the eyes of an elephant -- objects look smaller, which is great if you are shooting Gulliver’s Travels, but not for much else."

With the help of additional test shots, Hays explained: “You have to remember that depth disappears at a distance anyway so it is unnatural to try and create it with wide lens spacing. And wide-angle lenses give more depth than telephoto shots, which give that cardboard-cutout feel people talk about. But you can’t get too close to a face with a wide angle, or the nose elongates."

Hays and RealD co-founder Lenny Lipton think that the best way to solve problems of this kind “may be to shoot with too-widely spaced lenses and then use tools in post production to adjust the view,” Hays said. “That would mean we can go back to using side-by-side cameras, instead of beam-splitting rigs, which give smaller interaxial spacing but lose a stop of light in the half-silvered mirror.” But post-production tools for narrowing lens spacing haven’t been created, he said. The technique would also be good for glasses-free autostereoscopic 3D “because it lets you create a range of views between the extreme left and right,” Hays said. “But for autostereo we are going to need four times the HD resolution. If you create nine views that reduce resolution to a ninth or tenth, you end up with images like an e-mailed photo. And good autostereo may need up to 27 views. Also viewers can’t move their heads. So you could say it’s the ideal date movie."

As for the current 3D craze in Hollywood, Hays thinks people “won’t continue to pay for 3D screenings just because they are in 3D,” he said. “We have to get back to traditional storytelling, and use 3D to help tell the story. Now that the studios see 3D TV coming into homes they are more comfortable about making comedy and live action drama and thrillers in 3D.”