Okhay, A very interesting question was asked by Vikrant Gupta (user of Facebook Third Dimension Knowledge Group).
He asked that "Why do we use two colors "red and cyan" only while converting movies into 3d or even watching them?"
So, as the question is really interesting and informative I decided to make a blog on it.....
I am explaining the answer more than you asked so that others may also have the benefits.
In a real world we see things in Three dimension. We understand distance using parallax based on the difference between what the right eye sees and what the left eye sees. This is because of the distance in our eyes (which is approximately 2 inches). Now lets see how we see in real world. There are two Photoreceptors in our Eyeball/Retina known as Rods and Cones. These Photoreceptors are the cells in eye's retina which convert light electromagnetic radiations in to the biological process which our brain can understand. Now when we see something our brain perceives the slight shift in the images because of the distance in our eyes. And then brain composite two images to generate understandable depth. These Photoreceptors are responsible to send the signals to the brain and we understand and see the objects or surrounding in front of us.
He asked that "Why do we use two colors "red and cyan" only while converting movies into 3d or even watching them?"
So, as the question is really interesting and informative I decided to make a blog on it.....
I am explaining the answer more than you asked so that others may also have the benefits.
In a real world we see things in Three dimension. We understand distance using parallax based on the difference between what the right eye sees and what the left eye sees. This is because of the distance in our eyes (which is approximately 2 inches). Now lets see how we see in real world. There are two Photoreceptors in our Eyeball/Retina known as Rods and Cones. These Photoreceptors are the cells in eye's retina which convert light electromagnetic radiations in to the biological process which our brain can understand. Now when we see something our brain perceives the slight shift in the images because of the distance in our eyes. And then brain composite two images to generate understandable depth. These Photoreceptors are responsible to send the signals to the brain and we understand and see the objects or surrounding in front of us.
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| Rods and Cones in Eye. |
Now lets take this principle to the 3D cinemas.
The movie which we watch in Cinemas works by projecting two frames from two different projectors on the screen in a quick succession. One frame is according to the perspective of left and the other is according to the right eye. This setup of two projectors is to generate a slight shift between two COLORED Frames. OK, Now we came to the real question, Why Colored?????
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| Avatar Movie screenshot showing a slight shift in colors. |
Olrite,
We will talk about Cone Photoreceptors first, Cones sees Red color easily. Now blue color wavelength is 475 nm which is comparatively higher as compared to red color which is approx 650nm (nm stands for nano meter if you are not a physics student). Rods sees blue color easily and are responsible for our dark-adapted, or isotopic, vision. The rods are incredibly efficient Photoreceptors. More than one thousand times as sensitive as the cones, they can reportedly be triggered by individual photons under optimal conditions. Now the things goes blah blah blah blah..... yeah I am a physics student so I know hell a lot of crap. OK lets make this simple....
Cones Photoreceptors work with Red color easily and Rods Photoreceptor works with Blue/Cyan color easily and moreover these two colors are choose in 3D movies because they work best because they are at the opposite ends of the visible spectrum. This is the reason why this Red/Cyan color scheme is used these days in 3D movies because of biological process and the spectrum position.
Now, Last thing is about the 3D colored glasses.
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| 3D Glasses. |
The rods and cones works in the eyeball that see red and blue, see the individual tones and our brain composites them. Now, As I told that Red and Blue are at the opposite ends of the visible spectrum so in the 3D glasses two different filters are used which is in red and cyan color. Red filter restricts the coming cyan frame and same is the case with the other one. So in a simple way, we can say the real world perspective illusion is made using the glasses which restricts one frame for left and other for the right eye. The human brain naturally combines the two 2 dimensional images into a single, which makes it like we are watching real world and creates the illusion of Three Dimensional scene.
These days a newer technique is used apart from 3D colored glasses. The technology is called Polarization. Which is more powerful then we discussed. If you want to know about this Polarization technique also you can ask questions about it in the group.
I hope this answer satisfy you.
Take Care.
Mohit Sharma
mht.shr@gmail.com
www.facebook.com/mht.shr
