WASHINGTON — On Friday ESPN will begin broadcasting select sporting events in 3-D, starting with the opening match of the World Cup between the host-nation South Africa and Mexico.
Following in the wake of Hollywood’s latest trend, the sports programming world is the next wing of the entertainment industry to try and revive the art of bringing the screen to life.
Having entertained audiences in one form or another since the 1850s, 3-D imaging involves simple concepts to help trick viewers’ brains into thinking the action is taking place right in front of them.
In order to understand how the brain processes a 3-D image, it is important to remember that our two eyes, located at different positions on our faces, each send a different image to the brain.
To better understand this, hold one index finger six inches away from your nose, and the other a foot away. When you alternately close your left and right eye, it appears as if your fingers change positions even though they haven’t moved.
Because most people don’t look at the world through one eye, this combination of the two images into a seamless view of the world is often taken for granted.
“The brain does really impressive computations really fast to extract one view from two perspectives,” said David Hoffman, who completed his Ph.D. in vision science from the University of California-Berkeley last week. “It has to calculate what the difference between the left and right eye view means.
The different perspectives create disparity, and that disparity is interpreted by the visual system as 3-D depth.”
If you notice, when you use one eye to look at the world, depth perception is severely limited.
The illusion of 3-D in movies and television programs is created by the use of two cameras, separated usually by few inches, filming the same object(s). A regular movie uses one camera per shot angle.
The two different shots are there to simulate the differing perspectives of the left and right eye. In 3-D programming, both images are actually displayed on the screen on top of one another.
The key to tricking your brain is in the glasses. Each lens is designed to block out one of the images, and let the other one through. So while the left eye is looking at one image, the right eye is actually looking at a slightly different one.
This combination of two different perspectives is what causes the added dimension of depth to be perceived by the brain, which makes the images pop off the screen.
“In a sense, all that is happening is the makers of these programs are mimicking the difference between the right eye and left eye views that you get in the real world,” said Lawrence Cormack, a professor of psychology and neuroscience at the University of Texas.
Tricking the brain into seeing something in three dimensions is also why some side effects like headaches and nausea can occur.
Your eyes begin to converge when an object moves closer to your face. If you put your finger a foot from your nose and move it slowly toward yourself, you will notice that your eyes will begin to cross. In 3-D, images are perceived to move toward you, causing a similar reaction by the eyes.
The problem is that your distance from the screen does not change as the object appears to come closer, meaning your eyes are straining to stay focused on the stationary screen while they must also converge on the moving image.
“In the real world, these two distances are always the same,” Hoffman said. “Our research has shown that conflict between convergence and focus distance do cause visual fatigue.”
Because movement is often simulated, there is a disconnect between what the eyes are telling the brain, and what the inner ear, which controls the sense of balance, is telling it.
“The visual system is telling you you’re moving around and interacting with this 3-D world, where as your inner ear is telling you you’re sitting in a chair,” Cormack said.
For ESPN’s first foray into 3-D programming, it is difficult to know what to expect, especially since each person reacts differently to the technology.
Colleen Lynch, with ESPN communications, said in an e-mail:
“We understand that there has been discussion of possible health risks associated with 3D. Through our more than three years of production testing, we have strived to produce compelling 3D content that has shown no signs of being disruptive to the viewer. However, we cannot control issues that fans may have with different types of technology used to deliver and view 3D.”
Cormack said he doesn’t anticipate there being more problems with headaches and eye strain than watching a 3-D movie because the screen will be smaller and the atmosphere less provocative.
“I suspect that it will be on average, less intense, but not because it’s sports versus movies, but because these things will be viewed on a smaller screen in a less immersive environment,” he said. “You won’t get that motion sickness component because you’re not sitting in front of this really big screen. The more bigger and immersive the environment, the worse those side effects can be.”