Shoot with two cameras.
Stereoscopic films are shot using two cameras mounted on a special stereoscopic rig also known as a “3D rig.” The purpose of the rig is to hold the cameras close together and approximate interocular distance between average human eyes.
Stereoscopic rigs vary in design and fall within two major categories. Beam splitter rigs allow camera visual axis to be placed closer together in order to match human interocular distance.
Side-by-side rigs are simpler in design and are used for hyperstereo shots where larger separation between cameras (interaxial separation) is necessary to accommodate for the distance of the subject. Both types of rigs may use precision adjustments and sometime remote controlled motors for lenses as well as camera positioning.