Abstract: A stereoscopic objective lens system for video endoscopes and borescopes includes two full-diameter doublets and two lens pairs forming a stereo lens set. A rotatable dual telescope is disposed between the two doublets and the stereo lens pairs, establishing a Galilean telescope associated with each stereo channel. The Galilean telescopes are each rotatable, preferably in convert, to be in or out of alignment with the system optical axis. When out of alignment, the Galilean telescopes have no effect along the optical path. When in alignment, the Galilean telescopes provide an increase or decrease in magnification, depending on orientation of the telescopes. The full-diameter doublets present equal-angle pairs from symmetrically disposed object points to the lenses of the stereo lens pair. This equal-angle property enables accurate object/image mapping onto the final stereo image pair, such that all parts of each left/right image can be mapped to within a fraction of a video pixel to each other.

Abstract: A stereoscopic objective lens system for video endoscopes and borescopes includes two full-diameter doublets and two identical half-diameter ball lenses. The full-diameter doublets collimate object points, imaging object points to infinity. The full-diameter doublets present equal-angle pairs from symmetrically disposed object points to the ball lenses. This equal-angle property enables accurate object/image mapping onto the final stereo image pair such that all parts of each left/right image can be mapped to within a fraction of a video pixel to each other.

Abstract: A stereoscopic objective lens system for video endoscopes and borescopes includes a full diameter collimator lens systems and a pair of half-diameter stereo lens systems. The lens systems can be formed of doublet lenses or a combination of singlet and doublet lenses, or of gradient index lenses, or of a mixture of such lenses. The full-diameter lens system collimates object points, imaging object points to infinity to present equal-angle pairs from symmetrically disposed object points to the small stereo pair. This equal-angle property enables accurate object/image mapping onto the final stereo image pair, such that all parts of each left/right image can be mapped to within a fraction of a video pixel to each other.

Abstract: A stereoscopic objective lens system for video endoscopes and borescopes includes two full-diameter doublets and a double set of two half-diameter identical doublets. The full-diameter doublets collimate object points, imaging object points to infinity. The large collimator doublets present equal-angle pairs from symmetrically disposed object points to the small stereo doublet pairs. This equal-angle property enables accurate object/image mapping onto the final stereo image pair, such that all parts of each left/right image can be mapped to within a fraction of a video pixel to each other.

Abstract: Relay lenses for endoscopy include an axially symmetrical three-part optical component having a thin symmetrical negative element interposed between identical, substantially spherical outside elements; and an axially symmetrical five-part optical component in which the three-part component described above is disposed between two additional outer components.