Three dimensions, twice as difficult
By Brett Eppley
Today, 3-D technology continues to grow and diversify, and thanks to people like Chris Eller, the rest of us just might understand how it all works.
Eller, a telecommunications graduate student, specializes in 3-D cinematography and teaches a class on the subject.
When it comes to filming in 3-D, two cameras are used at once. Those cameras are placed side-by-side, mimicking the distance between the eyes. When the eyes see the two slightly different reels of film, the brain creates the three-dimensional images seen in theaters.
“You need to play it back in such way that the left eye only sees what the left camera recorded, and the right eye only sees what the right camera recorded,” Eller said.
To make sure that each eye sees the correct images, a few techniques are used, the most popular being polarization. This technique, which includes the use of glasses, is the one most familiar to audiences.
One camera’s film will be polarized for one direction, and the same for the other. Polarization only allows light vibrating in a certain direction to pass through the glasses and the film. The glasses worn in theaters will be matched for either side of the film. In doing so, the glasses make sure that each eye sees the correct images.
When it comes to auto-stereo — or Autostereoscopic — 3-D films without the glasses, the technology exists but simply isn’t as advanced as the more popular forms. According to Eller, the technique isn’t as consistent in creating depth on the screen.
“It’s being developed, and they’re making good progress, but it’s not quite as good in my opinion as the other methods we have right now,” Eller said.
“It’s just a very tough technology. There’s definitely a desire for it, but it’s just a very tough nut to crack.”
For now, most moviegoers will have to deal with wearing those 3-D sunglasses in the dark. Perhaps understanding the complicated technology gives viewers some perspective when shelling out the extra cash for a ticket.
Eller, and filmmakers like him, appreciate that audiences acknowledge all the work that goes into 3-D films.
“It’s basically twice as hard. Because you’re shooting two movies. You’re editing two movies. They just happen to be identical except a slight difference of perspective.”