Knowing How a Stereoscopic Camera Works

A stereoscopic camera allows users to capture images that are instantly rendered in 3D. Whether a photo or video camera, stereoscopic cameras contain more than one lens, each with their own separate image sensor or frame. To be able to achieve 3D stereoscopic images, it’s not necessary to shoot with a specialized camera. But first, you will have to know how stereoscopic images work and the role that the camera plays in creating this effect.

What Is Stereoscopy?

Stereoscopy refers to the technique of capturing images and rendering them as three-dimensional, with a realistic depth. Oftentimes, these images or videos have to be viewed with specialized 3D glasses. Stereoscopic images are created by overlapping the same image, but offsetting it by a couple of inches. This simulates human eyes and the way they work. In post-production, conversion of 2D images to 3D stereoscopy is possible by creating anaglyphic images of the material. To view the material correctly, a special red and cyan 3D pair of glasses is needed.

Types of Stereoscopic Images

There are several types of 3D Stereoscopic images. The most common is the anaglyphic image. When viewed without the help of specialty glasses, the images have outlines of red and cyan. This is the most common type of stereoscopic image, and this is the technique used for creating 3D movies.

If you remember the retro Viewmaster toy, that is another way of viewing 3D images. Through a specialty projector or viewfinder, you are simply viewing two identical images at the same time – one for each eye. The specialty viewer helps give the illusion of realistic depth.

There are many other types of renders for 3D stereoscopic images. There’s the autostereogram, a graphically-intense picture that can be viewed only with the proper technique. There are also the cross-viewing images, two images beside each other that will appear to have depth if the viewer crosses his eyes. 

The Stereoscopic Camera

To create the proper depth in 3D stereoscopic images, there are three basic elements you have to determine: the foreground, background and zero parallax. The foreground is the element in your image that will appear closest to the viewer, while the background is the image that will appear farthest. The zero parallax is basically the screen or the default zone. In rendering the images in post-production, the more divergence an element has, the closer it will appear to the audience. Divergence is the amount by which the overlapped images are offset. The more that they are misaligned, the closer they appear to the camera. Your objects in the background have the least divergence, and when viewed without specialized glasses, the red and cyan outlines can barely be seen.

To shoot stereoscopic images, you will either need a specialty lens that will convert your images into 3D, or you can mount two cameras beside each other. This will simulate the same image but as viewed by your left and right eye respectively. Do not angle the lenses or cameras to have the exact same framing. Each lens or camera is really supposed to be pointed straight, giving you two images that are similar but misaligned in framing. By overlapping the images in post-production and manipulating it as an anaglyphic image, you can achieve your 3D stereoscopic picture or video.