Before we talk about 3D vision of 3D video camera technology, let us briefly touch on 3D vision in nature. Why was there ever 3D vision, why wasn’t 2D vision good enough for animals?
3D videos in nature
There would be no 3D HDTVs, 3D cameras, 3D camcorders or 3D movies if a 3rd dimension in the form of depth did not exist in nature. Fortunately god created a 3rd dimension so that there could be all this good stuff and you could go online today and spend thousands of dollars to buy a 3D video camera!
Why would 3 dimensional vision be important in nature?
As you may have already heard, not all animals have 3D vision. All the carnivores (animals that have to hunt) and some omnivores like you and I are gifted with 3 dimensional vision. Why? Because we have (had) to hunt! Imagine a Cheetah chasing Gazelle without 3D vision! The Cheetah would know his left and right, up and down but would not have an idea about depth (or what is closer and what is further from it). If Cheetahs had 2D vision, their hunting Gazelle would look like Tom missing Jerry every time Tom tries to catch Jerry! The world would be a lot different.
Animals with 3D vision or binocular vision have their eyes placed at the front of their faces. Forward eye placement provides the carnivorous animals with a greater degree of binocular vision. With binocular vision, both eyes can focus on a single object at the same time providing a greater ability to judge distance (depth perception). However, these two images are not the same because the two eyes are located at slightly different angles and slightly different positions. This produces something called binocular disparity. It is this ‘disparity’ that helps the brain to Photoshop a 3D image!
In contrast, herbivores such as cattle have 2 dimensional vision. Their perception of depth is poor. Animals with 2D vision or monocular vision (meaning they may only see objects with one eye at a time) have their eyes placed laterally on their heads. The two images of the Cheetah and Cow shows this clearly! The yellow spot on the image is to show that animals with monocular vision will see a lot of things only with one eye!
3D images – 2 images of the same thing from 2 slightly different angles
When a Cheetah or for that matter you and I see an object, we see it with both our eyes at the same time. Even though we see the same image, the two eyes receive two slightly different images coming from two slightly different angles (binocular disparity as explained earlier). The brain needs these two slightly different images to process a 3D image.
If 3D cameras or 3D camcorders were to be produced (which already did happen), it was necessary that technology was able to produce two slightly offset images just like our two eyes did.
Stereoscopy – the magic of 3D video camera technology
In nature, when we perceive depth, it is no illusion. We perceive depth that actually exist! However, when you’re watching a 3D movie on a 3D TV or 3D movie theater, you’re seeing 3D on a 2 dimensional/planar surface. Therefore for you to perceive a depth that in actuality doesn’t exist, the brain needs to be fooled! Using two lenses, 3D cameras (still or video) are able to capture two slightly different images and make our brains believe that what you’re seeing is 3 dimensional. This is known as stereoscopy or stereopsis. Everybody knows about stereo music right? That’s music heard from both your ears, each slightly different. Simply put, stereoscopy or stereo vision is seeing with both eyes, two slightly different images. These are not exact definitions, then again this is not a scientific document either. Our intention is to make people without a hard core science/technology background understand the principles of 3D video camera technology.
Two lenses of 3D camcorders capture two different images
As you can see from this image, 3D cameras have two lenses. It is these two images that make 3D video recording possible. Every 3D camera including the first Panasonic 3D video camera or the latest Aiptek pocket 3D HD 720p video camera has two lenses. Once 3D video is recorded, it has to be played on a 3D source (3D blu ray player), the signal has to be sent to a 3D display device (3D TV or 3D projector) and watched using 3D glasses. That’s a whole new topic and will be covered elsewhere.