I’ve decided that it’s time I waded into the argument about 3D cinema with some of my thoughts. Firstly, I should tell you that I love the stereovisual effect – being able to trick your brain into giving the illusion of depth in an image where none exists. It has fascinated me ever since I was a child. At one point I had a large collection of holograms, and even now I own three 3D cameras – two of them use film, and one I hacked together myself to take digital 3D pictures. In the last year I’ve taken more 3D photos than 2D ones. Based on this I consider myself to be far more knowledgeable about the practicalities of 3D than almost anyone else you might have heard talking about it, outside the industry.
The simple fact is that making a 3D image is not comparable to making a 2D image. To believe that to make a film in 3D, you simply make it as you would in 2D, but using a 3D camera rig, is creative suicide. Likewise, to take a film which you’ve made in 2D, and then before you release it, change your mind and use CGI to retroactively convert it to 3D is to show an ignorance of the peculiarities of 3D film which is unthinkable – especially if you are a major Hollywood studio and your film is a massive financial undertaking which you are relying on doing well.
What am I talking about? Well consider this:
If you were looking at a person standing about 20 feet from you, then both your eyes would be pointing very slightly inwards so that they converge at the same place. Also your eyes would both be focussed on her 20 feet away. Now let’s assume she moves to a point 10 feet from you. Your eyes, in order to still be converging on her, have to point slightly more inwards than they were before – this is what allows your brain to create depth perception. Also, your eyes will now both be focussed 10 feet from you.
So what happens in a 3D movie? Well, if the screen is 20 feet from you, then to see the girl in her original position your eyes would be converging 20 feet from you and focusing 20 feet from you, just as they were in real life. But if she (in the film) moves to 10 feet in front of you, your eyes now converge 10 feet in front of you, but they are still focused on the screen, which is 20 feet in front of you, not 10.
If this is the first time you’ve seen a 3D film, it is probably the first time ever that your eyes have been converging and focusing at different distances – which causes eye-strain. The further objects are from the plane of the screen, depth-wise, the worse the eye-strain will be.
In order to make your 3D film as pleasurable to watch as possible, you have to try and keep the point of interest in a scene as close to the plane of the screen as possible – especially if the shot lasts for more than a second or two. Also, it’s best to avoid shots where the extremes of depth are very great. If you have more than one point of interest – such as two people having a long conversation, you should try and frame them so that they’re both as close as possible to the plane of the screen.
So what does this mean in practice? Well let’s imagine a scene from a film I’ve just made up: Our hero (let’s call him Tom) is tied up in a chair in a large empty room. Another man (let’s call him Bill) is beating him. Suddenly, a door opens in the far wall and a man steps in. Bill goes over to talk to the man for two minutes, all the time Tom is looking round trying to work out how to escape. The scene is one shot.
So, how would you frame that in 3D? Well the scene starts on Tom, so you could have him as close to the plane of the screen as possible to minimize eye-strain. But then when Bill walked into the background and was point of interest for two minutes, he’d be causing eye-strain. But if the background was on the plane of the screen, then the start of the scene would cause strain and also, Tom would be so far in the foreground that he’d be practically in your lap. So you put the plane of the screen somewhere in the middle distance, have Tom floating in front of the screen and the man behind it and hope that that minimizes the strain. Problem solved, yes?
Well, no. There’s another problem. If you frame a 3D shot so that everything in it is behind the plane of the screen, then it’s like you’re looking through a window. If something goes off the edge of the screen, it’s as if the object disappeared behind the window frame. But if something is in front of the plane of the screen, and that goes off the edge of the screen, then a weird effect happens. Because part of the object is no longer visible, but there’s nothing which could logically be obscuring it, you’re left with the effect of having half an object hovering in front of the screen.
So if our scene ended with Tom struggling in his seat, and tipping the whole lot over, with half his body exiting the side of the screen, then in 3D we’ve now got half his body weirdly hovering in front of the screen. So we have to set the plane of the screen on Tom so this doesn’t happen, but now we have a 2 minute dialog taking place in the far distance giving everyone eye-strain. The whole thing is just a mess. If our director is not aware of the problems of 3D, or if the film’s been retroactively converted, the whole thing could be filled with shots like this. Almost anything a cinematographer would normally do to make the frame interesting has the potential to ruin it in 3D.
So what works well in 3D? Ironically, unless you have a major grasp of the technical and artistic issues and structure your film around them, the best 3D shots are those which, pre-3D, were among the dullest. No unusual camera angles; Some depth, but not too much; Almost all the points of interest occurring on more or less the same plane; Nothing in front of the plane of the screen passing off-screen; etc…
So is it just a gimmick? Well, yes and no. The thing film-makers have to realise is that it’s an entirely different way of thinking about shooting a film – it’s not just like shooting in colour rather than black-and-white. There are directors who have such a good grasp of the technical and artistic aspects of film-making that they can work within the limitations of the format and still produce artistically interesting images – people such as Jim Cameron, and the Pixar gang. Until almost everyone else has undergone a major re-education about 3D, any films they produce are almost inevitably going to be disappointing. There is the potential for 3D to herald a whole new artistic and creative era for movies, but the current rush to have everything in 3D – whether the director wants it or not – without seemingly understanding what that entails, is making it look like a gimmick.
Certainly I won’t be bothering with “Clash Of The Titans 3D” any time soon.