Abstract: A high-resolution objective for large-format photography has a pair of positive meniscuses flanking a stop area forming a lens aperture; and a respective negative cemented doublet on a side of each meniscus turned away from the stop area, the positive meniscuses being composed of glass having anomalous partial dispersion, a refractive index n.sub.e <1.63 and a dispersion or Abbe number .nu..sub.e >63, the cemented doublets each having a negative lens element and a positive lens element, the negative lens element being composed of a lead-free, arsenic-free and antimony-free glass with an anomalous dispersion, a refractive index n.sub.e >1.63 and an Abbe number .nu..sub.e <50.

Abstract: This invention relates to a compact wide-angle lens which consists of five members. The first member and the last member are each divergent lenses of low deviation, which consist of low refractivity crown glass. The second member and the third member are convergent lenses made of high refractivity crown glass. The fourth member, which is the final member of the lens according to the invention, consists of a convergent lens and a divergent lens which are cemented to each other. Type of glass are used for this cemented member which have a very low difference in refractive index but a very high difference in dispersion. The convergent lens has a low dispersion and the divergent lens has a high dispersion. One of the two glass/air surfaces of the cemented member is aspherical. A lens such as this according to the invention has a maximum aperture ratio of at least 1:5.6 and an image angle of 105.degree.. The chromatic correction is well defined and is very substantially independent of the distance of the object.

Abstract: A double sided telecentic measurement objective for contactless length measurement in two-dimensional and three-dimensional space. The objective has an image-side optical system consisting of three elements equivalent to those of an object-side optical system but in the reverse order, including a cemented positively refracting lens element turned toward the object of image respectively, a collecting lens spaced by an air gap from the cemented lens, and a dispersive meniscus spaced by an air gap from the collecting lens. The widths of the air gaps between the collecting lenses and the meniscus are substantially greater than the widths of air gaps between the cemented lens elements and the collecting lenses.

Abstract: A measuring camera has a camera housing fixed to a rigid frame providing a reference surface against which an objective lens unit is held so that for a plurality of such units, all can have their respective projection centrums located at a fixed position within the housing. The frame has guides on which a sensor, e.g. of the CCD type, is mounted for movement parallel to the optical axis without play.

Abstract: An anamorphotic attachment for a projection objective has front and rear lens groups which have vertical diameters greater than their horizontal diameters and received respectively in an inner mounting tube and an outer mounting tube, the latter being connectable to the projection objective at its rear end. The inner mounting tube is fully received in the outer mounting tube and has thereon a shifting screw for moving the inner mounting axially within the outer mounting and a clamping screw actuatable to lock the two mounting tubes together, both accessible at the front end of the inner mounting tube within the outer mounting tube.

Abstract: A high-aperture wide angle lens consisting of a divergent action group on the lens side, an air space corresponding to 0.3 to 0.7 times or 0.25 times to 0.45 times the total overall height of the wide angle lens, an aperture diaphragm located approximately in the center, followed by a positive lens group consisting of a cemented element with total positive refractive power and a second convergent action group whereby the divergent action group on the lens side, and the second divergent action group each possess at least one aspherical surface. In such a four-lens or six-lens structural design, a typical image field angle of 130.vertline. or 146.vertline. or more is achieved at an f-stop of approximately 2.0. The high-aperture wide angle lens is particularly suited as a photographic field lens for electronic image processing systems such as CCD cameras.

Abstract: A wide-angle objective of compact construction and comparatively small diameter has its first lens element formed as a convex negative meniscus and its last or sixth lens element formed as a biconcave construction with the fourth lens element being a thick cemented lens.

Abstract: The described three-dimensional image viewing apparatus offers the possibility to perceive spatial objects which are reproduced through a pair of stereoscopic images as three-dimensional images, without the necessity to provide auxiliary optical means in the vicinity of the eye during viewing. For this purpose, an optical image forming system according to the basic principle of a microscope is provided between the two images (1a, 1b) of the pair of stereoscopic images and the two exit pupils (11a, 11b) for the eyes of the viewer, consisting of two fields lenses (2a, 2b) located immediately in front of the light-emitting images, two objectives (5a, 5b) a positive optical system on the eye side (9, 10) and of mirrors (3a, 3b, 4a, 4b, 8) for folding the ray paths located between the images (1a, 1b) and the positive optical system (9, 10). With such a viewing apparatus, unusually large exit pupils (11a, 11b) can be achieved, so that the viewer can move around considerably, without loosing contact with the image.

Abstract: In order to reduce the cost of a projecting lens system while providing excellent optical parameters for projection lenses of a series having different focal lengths but essentially the same high relative opening, all the lenses of the series utilize a common first component consisting of a positive lens, a positive meniscus and a negative lens. Only the second component is replaceable and comprises one lens or two closely spaced lenses. The second component for the longest focal length is preferably composed of low refractivity flint glass while the second component at the lowest end of the focal length range is composed of high refractivity crown glass.