The Science Behind 3D Cinema
The Science Behind 3D Cinema
If you’ve seen the movie Avatar in 3D, you know that cutting technology may be on the verge of returning cinema lovers to the golden age of films; a time when going to the cinema with friends was the best form of entertainment and a great way to spend a Saturday night. Film producers and movie houses hope so, as they struggle to sell tickets in this internet age. Even television producers are hoping to get in on the action to keep viewers at home and tuned in. But beyond all the competing interests behind 3D technology, how does it actually work?
To understand this we first need to know how the human optical system works. Due to the space between the eyes, usually around 6 cm in the average adult, both of your eyes see a slightly different image at any given time. The images are then sent to the brain where they are “overlaid” into a single image. The difference in the images created by the space between the eyes is what creates natural depth perception.
In the early days of 3D cinema, action was captured using two different cameras similar to the two human eyes. Each one placed in a separate position to capture a slightly different image. One camera filmed with red light while the other with green, creating two distinct images on the screen which would be filtered by those cardboard glasses with the coloured lenses. The two separate images spaced slightly apart on the screen simulated in the brain the natural process of the eyes.
While this technology worked well in producing 3D images, the use of red and green light distorted the natural colour of the film and made it look awkward. Modern technology solves that problem by concentrating on how light moves rather than what colour it is.
In the 3D cinematography of today, dual images are still projected on the screen, but they are distinct according to the way the light is projected. Under normal conditions, light travels out from a source and is dispersed as it travels through the air. But with new 3D technology the light of each image is concentrated to mover either to the left or the right. 3D glasses take advantage of this directional projection with each lens filtering out the image it doesn’t want. The result is, once again, a simulation of the natural eye function which produces the 3D image.
The best part of modern 3D technology is a noticeable lack of colour and image distortion. That’s because the human eye doesn’t really care what direction the light is travelling in, where it does care what the colour is. By taking colour out of the equation and putting direction in its place, we can now have films which are stunningly beautiful in colour and texture while still being 3D.
Where technology will take us next has yet to be seen. Will the current technology ever be adaptable to the home television market? Will we ever reach a time when holographic images will replace conventional 3D? No one knows for sure, but it promises to be an exciting ride.
Tags: 3d cinema, 3d science, 3d tech
