Terms You Will Meet
Very realistic drawings can be made using vanishing point perspective. As in the real world, things get smaller in size as they recede into the distance. By adding colors, textures, reflections and the like these drawings can be made very life-like. However, since they
are a single image from a single perspective they are not true 3D images although they are often called 3D. In movies, stereographers refer to their craft
as "Stereoscopic 3D" or simply "S3D" to differentiate it from 3D drawings or computer graphics.
It helps to start off with the best possible vocabulary. Here are some of the keys words you will encounter as you begin to explore stereo photography (these and many other terms are discussed in the glossary):
- 3D, sometimes spelled 3-D, refers to the three dimensions— width, height and depth. 2D refers to width and height.
- Binocular refers to having two eyes which enable most of us to see in 3D.
- Stereo vision (or more technically stereopsis) is our ability to perceive depth so we can judge the relative distances of objects. Binocular vision is necessary for stereo vision.
- Parallax refers to the apparent displacement of an object viewed from two different points. Parallax is caused by binocular vision and determines the scene's or photo's disparity.
- Disparity, caused by our binocular vision and parallax, is the offset of the images that fall on the retinas of each eye that allows us to see depth. This disparity is captured in a pair of stereo photos allowing most of us to see the image in 3D.
- Stereo pair refers to the left and right images that correspond to the scene as seen through the left and right eyes.
- Fusion refers to the act of viewing a pair of 2D stereo images in such a way that the brain combines them into a single 3D image.
- Stereo window is a virtual window that appears on the surface of the medium on which you fuse a stereo image. It seems as if you are viewing the 3D scene through this window.
- Stereographer is what you are when you take stereo photos.
- Stereoscopy refers to the capture and display of images that create the illusion of depth.
- Stereo viewer is any device that makes it easier to fuse 3D images.
- Homologous points are identical points in both images in a stereo pair—perhaps a person's pupils. In the superimposed images, the distance between these points is their disparity.
- When you press the Fuji Real 3D camera's parallax control you can see both images in a stereo pair and their disparity. If you press the Parallax button to reposition the stereo window, the percentage change is displayed on the monitor.
- Hold a pen about a foot in front of you and stare at it with both eyes. As you do so you'll feel your eyes converge (convergence) as the pen comes into focus. While still looking at the pen notice how the background forms a double image (disparity). If you then refocus on the wall behind the pen, it will come into focus and you will see two images of the pen.