3D Post Conversion: From Traditional 2D Filming to 3D Theatrical Release

Prior to the second wave of 3D theatrical releases, many films were already released in anaglyph 3D using the red-cyan glasses during the 1970s. So what's the primary difference between the older 3D and the newer 3D? Instead of the red-cyan glasses used not only for film but also for computer games of the past, the early 2000s started employing a new technology for 3D viewing called stereoscopic 3D or stereoscopy.

Stereoscopy is a filming technique that allows the recording of three-dimensional visual information or creating the illusion of depth so viewers can perceive the scene in 3D through the process called stereopsis.

Another interesting function of stereoscopic 3D is that it can be used for films intended to be shot in 3D already (using 3D cameras or 3D rigs) or films intended to be shot in 2D, then converted into the 3D format through 3D post conversion. This latter one allows even the older films to be re-released in 3D format: especially classics that may have a market for new theatrical releases and even home video releases in 3D. For instance, films like Lord of the Rings, Jaws, Alien, and many other classic favorites may soon be enjoyed in 3D glory through 3D post conversion.

More about stereoscopic 3D films as part of film history: Motion Picture History: A Chronological Look

Louis Letterier's Clash of the Titans and Tim Burton's Alice in Wonderland were shot in 2D, then post converted to 3D.

Advantages of 3D Post Conversion
The primary advantage of 3D post conversion is the fact that it gives the chance for older films to be converted in 3D. It also allows new films to be shot in 2D (a medium that experts already know by heart) instead of being limited in their shooting set-ups due to the physical and technical requirements of shooting with a 3D camera or 3D rig, then post convert the film for 3D release.

The main difference between using a 3D camera or a 3D rig is that, a 3D camera is like two film cameras combined together with the same concept as how the two human eyes work together to see things; while a 3D rig uses two typical 2D cameras with 3D rig for proper placement of each camera separately recording the same subject at the same time.

A 3D camera is like a two-in-one camera, meaning, there are two lenses, two magazines for the film stock, among other things. It records two separate images (left and right) which are then processed in post to employ the right distance in between the images so that they work as a 3D film when wearing the polarized 3d glasses. A 3D rig considerably applies the same concept by setting up two 2D cameras within correct distances from each other during the shoot to capture the subject. The footage undergoes 3D processing during post-production.

3D cameras and 3D rigs require a stereographer to work with the director, cinematographer, and production designer to make sure that the blocking of the actors, the mounting of props and sets, and the lighting are favorable to what the 3D set-up can utilize well. This generally limits the filming process as the creative people in the production need to sacrifice certain kind of shots so that the film works for the 3D environment. And so, there are filmmakers who prefer to shoot in the familiar realm of 2D filmmaking, then just convert the 2D movie into 3D afterwards. While they also consult with the stereographer, they have more freedom to shoot without the physical hassles of the bulky 3D camera set-up.

Present Problems with 3D Post Conversion
There is a difference in quality between films shot in 3D and films converted into 3D. On my personal experience with the films Avatar (shot in 3D using the best existing technology as accommodated by its hundreds of millions of dollars of production budget), Clash of the Titans, and Alice in Wonderland (both shot in 2D, then converted into 3D during post), the 3D theatrical screenings show:

Avatar: Jaw-droppingly good. The complicated, annoying, overly technical, and very tedious process of polishing the original footage using 3D camera really pays off. The 3D camera is meant for 3D filmmaking and it truly delivers for that technical amazement on the stereoscopic 3D technology.

Clash of the Titans: Very bad 3D conversion. It's technically not very polished and not utterly convincing 3D. It doesn't have that "digitally organic 3D excitement" as what Avatar gets to offer. The post conversion process takes endless rotoscoping to provide layers that can be separated to fake a different perspective in an originally 2D scene. It is a given that the post guys can tediously push and pull things away to enhance the depth, but the very content within each layers ultimately don't have the right depth which makes the process not in par with 3D shooting. Perhaps, as the technology progresses, 3D post conversion may be able to perfect the calculation of proper distances when pushing and pulling away things to enhance depth. And by that time, 3D post conversion may become a much ideal choice for filmmakers.

Alice in Wonderland: Not even half as impressive as Avatar, but much better than Clash of the Titans. While it considerably uses the same process as Clash of the Titans, what makes it work better is mainly the fact that it mostly uses computer-generated visuals, except for the actors who were shot live. Yet, even the actors were mostly altered in post. For instance, Helena Bonham-Carter's Red Queen character has a much shorter height and a much bigger head. While Clash of the Titans have many CGIs as well, Alice in Wonderland has more CGI works than it. Another thing that helps Alice somehow work better in 3D is because of Burton's grand visual treatment for it. The colors (from the actors' make-up and wardrobe to the props and sets) help things pop out better in 3D. It's not as dark and monochromatic as Clash of the Titans and more visual elements of Alice get to enhance depth.

Read more about 3D:

The Top 5 Best 3D Movies List

The Top 5 Worst 3D Movies List

How to Make Your Own 3D Photo and Viewing it with Anaglyph 3D Glasses