A stereo camera
is a type of camera
with two or more lenses. This allows the camera to simulate human binocular vision
, and therefore gives it the ability to capture three-dimensional images, a process known as stereo photography
. Stereo cameras may be used for making stereoviews
and 3D pictures for movies. The distance between the lenses in a stereo camera (the intra-axial distance) is about the distance between one's eyes (known as the intra-ocular distance) and is about 6.35cm, though a longer base line (greater inter-camera distance) produces more extreme 3-dimensionality.
In the 1950s, stereo cameras gained some popularity with the Stereo Realist and similar cameras that employed 135 film to make stereo slides.
3D pictures following the theory behind stereo cameras can also be made more inexpensively by taking two pictures with the same camera, but moving the camera a few inches either left or right. If the image is edited so that each eye sees a different image, then the image will appear to be 3D. This method has problems with objects moving in the different views, though works well with still life.
Stereo cameras are sometimes mounted in cars to detect the lane's width and the proximity of an object on the road.
Not all two-lens cameras are used for taking stereoscopic photos. A twin-lens reflex camera uses one lens to image to a focusing/composition screen and the other to capture the image on film. These are usually in a vertical configuration. Examples, would be a vintage Rolleiflex or a modern twin lens like a Mamiya.
Types of stereo cameras
There have been many types of cameras that take stereo images, most of which are no longer manufactured. The most notable vintage types are:
- Nimslo 3D
- Stereo Realist
- Kodak Stereo Camera
- Jules Richard Verascope
- RBT In the modern 3D world, a several thousand dollar RBT camera is made in Germany by rebuilding two 35mm high end cameras into an integrated & unitized stereo camera.
- Loreo 3D Lens in a Cap (Hong Kong) - an accessory device, which incorporates a pair of small closely spaced lens, and a simple mirror box as an attachment for many modern SLR digital cameras. The latest version has 25mm wider angle lenses. Loreo also makes currently, a cross-view 35mm film only, 3D CAMERA, (model 321) which takes "deeper" stereo images, with a wider mirror system, sold with a folding print viewer included.
- Plenoptic camera - A lenticular array of microlenses is situated at the imaging plane of a single-lens camera, effectively creating a dense array of low image resolution optic structures, making the camera akin to a compound eye. The concept of the plenoptic camera was conceived for integral imaging in creating a type of autostereoscopic image. A digital camera prototype of this is the Adobe Light Field Camera.
Use of dual cameras
Modern low cost digital cameras, and even dSLRs, can be mounted in pairs, with both triggered simultaneously. For nonmoving images this can be done by pressing both camera actuating buttons simultaneously, but this is not sufficiently accurate for moving objects. Certain camera models can accept modified programming from an image chip, and the software to trigger a slave camera from a master has been developed as open source
- 3-D Review Online Magazine 3-D products and services are reviewed monthly at www.3-Dreview.com
- http://www.stereoscopy.com/cameras Detailed information about 3D-Cameras (Stereoscopy.com)