Avatar: The Way of Water, 2022. Courtesy Disney.
Originally introduced by English physicist Charles Wheatstone in 1832, stereography is a photographic technique that combines two images taken at slightly different angles of the same scene to create the illusion of a third dimension. Streamlining the process was the introduction of a twin lens camera in 1856 which took into account that in order for the brain to process the stereo picture, the intraocular distance between the eyes had to be two and a half inches apart which meant that the two photographs were simultaneously captured only a few inches apart from each other. The expansion into feature films began in 1922 when Harry K. Fairall co-directed and shot The Power of Love using a red and green anaglyph system developed with business partner Robert F. Elder which superimposed the red and green images and produced a stereo effect when they were viewed through their corresponding color filters.
However, it was not until 30 years later that the studios truly embraced the format, commencing with Bwana Devil (1952); the adventure thriller took advantage of the Natural Vision 3D camera system which created a variable parallax that eliminated eye strain. A box office sensation was born with 57 3D features being released between 1952 and 1954, among them were Kiss Me Kate, Dial M for Murder, Creature from the Black Lagoon, House of Wax and The French Line. To enhance the single apartment setting for Dial M for Murder, Alfred Hitchcock had the Natural Vision cameras placed in a pit and shot upwards so to increase the depth and sense of claustrophobia. Afterwards Hitchcock famously observed, “It’s a nine-day wonder, and I came in on the ninth day.” Hitchcock was proven wrong as stereography has never disappeared and had a second wave in the early 1980s with a heavy reliance on dual 70mm projection. The technique was seen as means to refresh franchises resulting in Jaws 3D, Amityville 3D, and Friday the 13th: Part III getting the extra dimension to add to the scares. Even Francis Ford Coppola, George Lucas and Michael Jackson got together for the Disney EPCOT presentation of Caption EO (1986) which took advantage of 3D to heighten the experience of laser impacts, smoke, asteroids and star fields.
When Superman Returns (2006) had a couple of key action sections converted to 3D, stereographic conversion began to take hold in Hollywood. The third wave occurred three years later, in 2009, when audience members got to visit Pandora. “Avatar was like, ‘Oh, my god. I haven’t seen this before. This is amazing,’” recalls Sebastian Cramer, Director, Cinematographer and Founder, Screen Plane. “It had a perfection that only James Cameron could do because he has this freedom to say, ‘No. I’m not ready. We have to wait.’” Unfortunately, there were studio executives who could not afford to wait, meaning that 3D releases of Clash of the Titans and The Last Airbender were rushed and not given enough time, budget and resources to be converted properly, and were heavily panned by the critics.
Cameron’s understanding of the format is on full display in the sequel released 14 years later with, Avatar: The Way of Water (2022). “…it is quite interesting because there are these fully CG aerial shots that you would imagine have a lot of 3D potential,” remarks Cramer. “However, they are two identical flat images. This is because there is a tendency when you see a wide shot, especially an aerial when you’re looking down, it looks like a miniature world. That was a smart decision. A stereographer would say, ‘I have this amazing shot. Let’s do it in 3D.’ And everybody is blown away but they look at a miniature world which is taking away from the story. This is what went wrong with the last boom of 3D. It had no time to develop as its own cinematic language and there were only a few people who took it seriously, like Cameron, Wim Wenders, and Ang Lee.” Ang Lee is responsible for Life of Pi (2012), Billy Lynn’s Long Halftime Walk (2016), and Gemini Man (2019), and wrote to Cramer saying, “There is nothing that touches me as much if I can see a close-up on a face in 3D.” Cramer explains, “That’s something different from saying, ‘We want to have all of these stones explode and fly into the audience’s face.’”
Native stereo is one way to add the extra dimension, with Walt Disney Animation Studios and others relying upon 3D conversion. “We’re able to add cameras in Maya [a 3D software program] like a stereographer who is shooting it native and create planes in space,” explains Katie Tucker-Fico, Stereographic Supervisor, Walt Disney Animation Studios. “With those planes we are able to have our eye fixed or convergence point at the same depth from shot to shot because we want it to be comfortable for their viewer, so the eyes aren’t jumping back and forth. Whereas if shot natively, they might have to do a post process to put the camera position where they wanted the depth to be, like a continuity pass. We’re all doing the same thing but in a different way.”
The stereographic conversion process is mapped out before the start of every show. “It could be that we convert the 2D versus the 3D. “Sometimes an image asset will be projected on a card in space and we might do a depth map to round out the image to add dimensionality if it’s something in 2D,” explains Tucker-Fico. “On Wish (2023), some of the effects were 2D and we had to put them into the space with the 3D element so we’ll paint depth maps to make it fit in the space.” The bubbles were fun to create for Wish. “In 2D, the bubbles are flat to each other. But in the 3D version we brought them out really far, and with the song and music it made the moment more magical. And you can see in the bubbles. It was one of the first sequences where we had a lot of people in the building come and ask me, ‘Can you show it again?’”
The steps for stereo conversion have remained the same. “It’s roto, depth and in paint,” explains Emma Webb, Stereoscopic Supervisor, Marvel Studios. “We have added a visual effects augmentation team and utilize them when we can’t get elements from the visual effects vendors. Let’s say that we have smoke and can’t get that in time to utilize it. Our in-house team will find ways to remove that smoke, rebuild it, and place it back in, essentially making a visual effects element of that plate.” The studio also uses 3D to elevate subject matter. Webb shares, “For our Ant-Man movies we had a fun time enhancing what [the filmmakers] were trying to tell. They had a difficult time in 2D with Ant-Man trying to make him look as tiny or big as he was meant to be. We were able to take it, enhance that, and make it feel even better in 3D.”
Over the years, the style of stereography has changed. “We remastered a bunch of our films for the Apple Vision Pro in HDR and watched The Avengers again which used a stereo style called ‘Party in the front,’” explains Webb “It’s basically tons of volume in the characters but then the background is close-up to their heads The problem with that approach is the convergence was all over the place. In one shot, a character was all the way behind the screen far back and your eyes are having a hard time to adjust, and the next shot they are far forward and out into your face. We have a mechanism here in our theatre where we can do a hit which is a horizontal image translation that basically shifts the entire scene or shot backwards or forwards. We redid a hit pass for that movie specifically to make sure that everything that you’re supposed to be looking at is at screen plane and makes it a lot more comfortable for your eyes.”
Cinema screens have been improved to produce a better theatrical presentation. “Over the last several years screen manufacturers have made significant improvements in the materials used in making 3D cinema screens to maximize brightness and maintain contrast levels for 3D presentations,” remarks Scott Hildebrandt, Director of Exhibition Technology Operations, Cineplex. “In addition, with laser projection now becoming more common, 3D has been given a much-needed boost in brightness.” The workflow for stereographic projection is minimal. “Theatre teams will build up their 3D movies in digital workstations using the content provided. The 3D movie ‘playlists’ contain cues that communicate with the projection equipment to automate the 3D filter to slide in front of the lens for a 3D presentation and away from the lens for a 2D presentation. The 3D filter will stereographically separate the images to the right and left eye, and the 3D glasses worn by our guests bring those images together.”
Hildebrandt singles out Avatar: The Way of Water as a premium 3D experience. “James Cameron raised the bar on how 3D imagery can create a realistic sense of depth and space versus simply placing objects into your field of vision. I was impressed with how he was able to bring Pandora to life with the use of light and environment right down to the small details in 3D.
Stereography has moved closer to emulating 2D filmmaking with Sebastian Cramer’s development of a macro rig that shoots 3D through a single lens. “It requires a lens with a large aperture,” Cramer explains. “In such an optical path you can separate a section for the left eye and one for the right eye. The maximum stereo base can only be about the half of the aperture diameter of this single lens. It’s only for macro shots. This rig can do a maximum of 10mm stereo base, but it's incredible for shots of insects and other little buggers as they can be right up to the front lens, so you have all the freedom for lighting, which is not possible on a mirror rig.”
As for home entertainment 3D, it still has a long way to go. “The problem right now is successful 3D TVs that look great without glasses have an eye tracking software that can only track one pair of eyes, which is completely pointless when you’re trying to bring it into your home unless you live alone,” observes Webb. “You have to get it to a place where even if it’s a limit of four, then people will start to want it again.” The biggest consumer innovation is the Apple Vision Pro but there is a monetary hitch. “It’s cool but really expensive!” states Tucker-Fico. “One day the price will go down so that people can buy it. It’s maybe the start of the future.”
Hildebrandt contemplates the future of theatrical presentation. “Holographic content is very impressive, but I feel that filmmakers and technology providers would need to work closely together in that space before exhibitors could take full advantage. Stereographic 3D can be used very well to convey a sense of depth and space to a film without being too ‘gimmicky.’ If filmmakers leaned on that we could see very immersive experiences in 3D films.”