Why 3D doesn't work and never will. Case closed.

By Roger Ebert on January 23, 2011

I received a letter that ends, as far as I am concerned, the discussion about 3D. It doesn't work with our brains and it never will.

The notion that we are asked to pay a premium to witness an inferior and inherently brain-confusing image is outrageous. The case is closed.

This letter is from Walter Murch, seen at left, the most respected film editor and sound designer in the modern cinema. As a editor, he must be intimately expert with how an image interacts with the audience's eyes. He won an Academy Award in 1979 for his work on Apocalypse Now, whose sound was a crucial aspect of its effect.

Wikipedia writes: "Murch is widely acknowledged as the person who coined the term Sound Designer, and along with colleagues developed the current standard film sound format, the 5.1 channel array, helping to elevate the art and impact of film sound to a new level. Apocalypse Now was the first multi-channel film to be mixed using a computerized mixing board." He won two more Oscars for the editing and sound mixing of The English Patient. 

"He is perhaps the only film editor in history," the Wikipedia entry observes, "to have received Academy nominations for films edited on four different systems:

• Julia (1977) using upright Moviola 

• Apocalypse Now (1979), Ghost (1990), and The Godfather, Part III (1990) using KEM flatbed 

• The English Patient (1996) using Avid.  

• Cold Mountain (2003) using Final Cut Pro on an off-the shelf PowerMac G4.

Now read what Walter Murch says about 3D:

Hello Roger,

I read your review of Green Hornet and though I haven't seen the film, I agree with your comments about 3D.

The 3D image is dark, as you mentioned (about a camera stop darker) and small. Somehow the glasses "gather in" the image -- even on a huge Imax screen -- and make it seem half the scope of the same image when looked at without the glasses.

I edited one 3D film back in the 1980's -- Captain Eo -- and also noticed that horizontal movement will strobe much sooner in 3D than it does in 2D. This was true then, and it is still true now. It has something to do with the amount of brain power dedicated to studying the edges of things. The more conscious we are of edges, the earlier strobing kicks in.


The biggest problem with 3D, though, is the "convergence/focus" issue. A couple of the other issues -- darkness and "smallness" -- are at least theoretically solvable. But the deeper problem is that the audience must focus their eyes at the plane of the screen -- say it is 80 feet away. This is constant no matter what. 

But their eyes must converge at perhaps 10 feet away, then 60 feet, then 120 feet, and so on, depending on what the illusion is. So 3D films require us to focus at one distance and converge at another. And 600 million years of evolution has never presented this problem before. All living things with eyes have always focused and converged at the same point.

If we look at the salt shaker on the table, close to us, we focus at six feet and our eyeballs converge (tilt in) at six feet. Imagine the base of a triangle between your eyes and the apex of the triangle resting on the thing you are looking at. But then look out the window and you focus at sixty feet and converge also at sixty feet. That imaginary triangle has now "opened up" so that your lines of sight are almost -- almost -- parallel to each other.



We can do this. 3D films would not work if we couldn't. But it is like tapping your head and rubbing your stomach at the same time, difficult. So the "CPU" of our perceptual brain has to work extra hard, which is why after 20 minutes or so many people get headaches. They are doing something that 600 million years of evolution never prepared them for. This is a deep problem, which no amount of technical tweaking can fix. Nothing will fix it short of producing true "holographic" images.

Consequently, the editing of 3D films cannot be as rapid as for 2D films, because of this shifting of convergence: it takes a number of milliseconds for the brain/eye to "get" what the space of each shot is and adjust.

And lastly, the question of immersion. 3D films remind the audience that they are in a certain "perspective" relationship to the image. It is almost a Brechtian trick.

Whereas if the film story has really gripped an audience they are "in" the picture in a kind of dreamlike "spaceless" space. So a good story will give you more dimensionality than you can ever cope with.

So: dark, small, stroby, headache inducing, alienating. And expensive. The question is: how long will it take people to realize and get fed up?

All best wishes,
Walter Murch