Here in the Palm Springs, CA area, we’re host to many visitors and snowbirds who arrive to escape real winters elsewhere, and enjoy the mild temperatures and almost always sunny days that us locals take for granted. As such, the area is an ideal venue for business conferences (but not in the summer months), and every February for a number of years Palm Springs has hosted the annual Hollywood Post Alliance Technology Retreat in one of the resort hotels in the valley.
The HPA retreat brings attendees from greater LA, the hub of the TV and movie post-production community, and others from across the country and around the world together to confab about the latest in post-production TV and film equipment and techniques, with seminars, a super-session, round tables and various equipment and technology displays on hand.
With the boffo box office success of Avatar and other popular 3D movies, and with the imminent arrival of 3D HDTVs in stores, it wasn’t much of a shock that this year’s retreat featured a 3D super-session on the event’s opening day. At last year’s event, 3D had been covered in a number of shorter segments, but this time it got to be the main event.
Two presentations stood out. One, by 3D filmmaker Wayne Miller of Action 3D Productions, whose body of 3D work includes the We Are The World video for Haiti relief efforts that was taped at the 2010 Grammy Awards, introduced the two types of 3D cameras used in production. For close-up work (where the subject is 30 feet away or less), a beam splitter type is used, which has two HD cameras positioned at 90° relative to each other, with a light dividing optical system out in front.
For shooting distances of greater than 30 feet, a more conventional-looking dual camera stereoscopic setup is used, featuring optically matched lenses that feature long focal lengths. From a cost of production standpoint, Mr. Miller confirmed that compared to a conventional 2D high def production, 3D will be more expensive to produce (no surprise there). For simpler productions that only require one or two 3D camera setups, the cost uptick would be in the 15-20% range, and for productions that require three or more 3D cameras, the cost increases to about 30-35% over 2D. He pointed out that over time, as more 3D productions evolve, cost differentials should shrink. During a brief Q&A session, Mr. Miller noted that James Cameron’s 3D hit Avatar benefited from “mild” use of 3D effects, an important consideration for a long runtime 3D movie.
Another notable presentation followed Mr. Miller’s, by visual science expert Dr. Marty Banks of the University of California-Berkeley, who explained why some people develop unpleasant symptoms when watching 3D (headaches, eye strain, even nausea in some extreme cases). Citing reference work that dates back to the early part of the last century (The Prescribing of Spectacles – A.C. Percival), Dr. Banks explained that we’re essentially wired for 2D vision, and that 3D presents discontinuities in the vision process that deal with focal plane (focusing on an object a certain distance away) and vergance (the stereoscopic difference angle between the left and right eyes).
When looking at an object in real life, our eyes converge on the object, at the same time focusing on the object. The relationship between vergance and focus remains a linear constant. With 3D however, there is a disconnect between the two. Citing Percival’s “zone of comfort”, Dr. Banks pointed out that if the disparity between vergance and focus is too great (i.e., outside the zone), then side effects are to be expected. By keeping the 3D effect within the zone, audiences can enjoy the experience with minimal risk of undesirable symptoms. Dr. Banks also noted that what is considered an acceptably close viewing distance in a 2D movie theater is most likely too close for comfort for a 3D event. That jives with my own experience watching Avatar in IMAX 3D – I sat in the second last row of the theater, and had a pleasurable 3D experience. I’m quite sure that if I’d been seated somewhere in the front rows, I probably wouldn’t have enjoyed it as much.