3D Explained
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.
3D Cinema: How Does it Work?
Are you a big fan of all those big budget Hollywood movies that are in 3D? Lots of people are lining up for the 3D version of films even though the admission price is much more expensive than the regular version. This is because with 3D you get to experience the movie with more depth. With hits such as the Avatar having a huge success in the 3D format more and more films will be coming out in 3D.
Since 3D is becoming popular these days have you ever wondered how it works? Lets discuss some of the basics of 3D and hopefully after you have finished reading this article you would have a better understanding of how 3D cinema works.
Theory Behind 3D
3D ( three dimensional) isn’t actually a new technology. It has been around since the early 1800′s when the Stereoscope was invented. This device enabled the users to view an image with an added depth perception. Although it was a crude device, nevertheless this is where 3D began.
The normal way movies are made is that the scene is shot using a single camera from a single perspective. When you would like to create a 3D scene you would have to record the scene from two perspectives. In a way, 3D filming is just like how a human being would see his surroundings. With our two eyes we can easily distinguish depth. This same principle is also applied in 3D cinema by using two sources to record the same scene. Two separate film rolls are used to record the scene, one to mimic the perception of your left eye and one for your right eye. Special cameras or advanced computer software is used to create this illusion of depth.
Techniques Behind 3D
Since 3D has been around for quite awhile there are numerous techniques used in applying it to cinemas.
The original method was called the Anaglyph technique. Have you been to a movie where you had to use glasses that had a red and green lens? That movie is using the Anaglyph technique in presenting 3D. In this technique, the image is made of two colors which are then superimposed but offset a little to create that feeling of depth. When viewed using the specially designed glasses, the brain would see a 3D image. This method is now making a comeback in High Definition movies, Blue-Ray discs and in the Internet.
Right after the Anaglyph, a new technique called the Polarization system was used to bring 3D to the cinema. This method also had to record the image from two different perspectives but used a different polarizing filter for each. The audience would still have to use special glasses to view the 3D image. Major 3D providers such as RealD and IMAX use this system in bringing 3D to the screen.
Equipment Behind 3D
Unlike its 2D counterpart, a 3D movie needs special theater equipment for it to be viewed properly. You might have noticed the growing number of IMAX 3D theaters right now right? The equipment used in these theaters differ from the regular ones. This is also one of the reasons why the ticket prices for 3D movies are generally higher.
Let us start with the projector since in my opinion this is the most important equipment in a 3D cinema. The projectors used to provide the 3D images are not the normal ones used in regular movies. The normal ones had a frame rate of 60 Hz while these 3D projectors have a frame rate of 120 Hz. As you can see the amount is doubled, this is due to the fact that more output detail is required in showing a 3D film. The 3D projector must also have a resolution of at least 2k (2048x1080p) for a clearer image on a wide screen. The most popular providers of commercial cinema projectors are Dolby 3D and IMAX.
The screen used in 3D cinemas are usually silver screens. Since a lot of light will be used due to the technology used in showing a 3D movie, a silver screen is used to provide more light and contrast. Did you know that the very first cinema houses used silver screens? This is where the term silver screen came from. White screens, which are much cheaper, soon replaced silver screens in cinemas. Right now silver screens are making a comeback in 3D movie houses.
We’ve got the projector and we’ve got the screen . Now it’s time for the sound system. A 3D cinema should not only provide a great visual experience but a great auditory experience as well. In an IMAX 3D theater, up to 44 speakers are used to provide you with surround sound. The speakers use 12,000 watts of power which ensures a fantastic viewing experience.
Lastly we need the glasses to be worn by the viewers to enjoy the 3D effect. These glasses are polarized and matched with the cinemas projector. So in essence, you can’t just use any type of glasses, they should be compatible with the projector used.
There are numerous projects developed right now for 3D to be seen in cinemas without the glasses. Although these are still in its initial stages they seem to be promising enough. Until the time comes when a method for viewing 3D movies without the glasses are needed, we really need to wear glasses to enjoy 3D movies.
If you take a look at the equipment involved in running a 3D cinema you would then understand why they are charging a higher admission price than the regular cinemas. 3D cinema equipment are much more expensive than your regular cinema equipment, making the high ticket prices reasonable enough.
Now that we have tackled the basics of 3D cinema you won’t be baffled by this technology the next time you visit your local 3D theater. As more movie studios produce 3D movies, more and more 3D cinemas would be created. If you haven’t seen a movie in 3D yet then now is the right time to do it. You’ll definitely experience it better in 3D.
