Abstract: A telephoto lens having an entrance pupil of between 80 and 110 mm includes a lens head and a focusing component. The lens head, as a first optical assembly, consists of four lens elements with a refractive power sequence that alternates in the light direction. The focusing component is a second optical assembly made of at least two lens elements and has a relative aperture of between 1:4.5 and 1:7.

Abstract: The invention relates to a digital viewing device, comprising at least one camera module, consisting of an objective (2) having a focal length fobj and an image sensor (3) having an image diagonal dSensor, and at least one electronic viewfinder, consisting of an eyepiece (9) having a focal length fOku, an image processor (5), a power supply (7) and an electronic display (10) having an image diagonal yDisplay, characterised in that to correct distortion of the image generated on the display the image processor contains at least one computer program with distortion correction algorithms and the computer program can be switched on by means of an activating element (6).

Abstract: A lens system with a fixed focal length includes five lens groups. The five lens groups include a first lens group, a second lens group configured as a focusing front group, a third lens group having a negative refractive power, a fourth lens group configured as a focusing back group, and a fifth lens group. The fifth lens group has a positive refractive power that is arranged in a stationary manner relative to an imaging plane in a lens barrel and both the focusing front group and the focusing back group are movable jointly relative to one another and to the lens groups arranged in a stationary manner in order to focus the fixed focus length lens system on objects at different object distances.

Abstract: A lens with a fixed focal length includes five lens-element groups, a first front lens-element group, a second lens-element group, a third lens-element group, a fourth lens-element group, and a fifth back lens-element group is arranged in a stationary manner. Relative to an imaging plane in a lens barrel and both the focusing front group and the focusing back group are movable jointly relative to one another and to the lens-element groups arranged in a stationary manner in order to focus the lens on objects at different object distances.

Abstract: A lens with a fixed focal length, includes five lens-element groups, a first front lens-element group, a second lens-element group, a third lens-element group, a fourth lens-element group, and a fifth back lens-element group that is arranged in a stationary manner. Relative to an imaging plane in a lens barrel and both the focusing front group and the focusing back group are movable jointly relative to one another and to the lens-element groups arranged in a stationary manner in order to focus the lens on objects at different object distances. The front lens-element group and the back lens-element group have a negative refractive power.

Abstract: A lens with a fixed focal length comprising including a first front lens-element group, a second lens-element group, a third lens-element group, a fourth lens-element group, and a fifth back lens-element group. Relative to an imaging plane in a lens barrel and both the focusing front group and the focusing back group are movable jointly relative to one another and to the lens-element groups arranged in a stationary manner in order to focus the lens on objects at different object distances. The front lens-element group has a positive refractive power and the central group and the back lens-element group have a negative refractive power.

Abstract: A telephoto lens having an entrance pupil of between 80 and 110 mm includes a lens head and a focusing component. The lens head, as a first optical assembly, consists of four lens elements with a refractive power sequence that alternates in the light direction. The focusing component is a second optical assembly made of at least two lens elements and has a relative aperture of between 1:4.5 and 1:7.

Abstract: A lens with a fixed focal length, includes five lens-element groups, a first front lens-element group, a second lens-element group, a third lens-element group, a fourth lens-element group, and a fifth back lens-element group that is arranged in a stationary manner. Relative to an imaging plane in a lens barrel and both the focusing front group and the focusing back group are movable jointly relative to one another and to the lens-element groups arranged in a stationary manner in order to focus the lens on objects at different object distances. The front lens-element group and the back lens-element group have a negative refractive power.

Abstract: A lens with a fixed focal length includes five lens-element groups, a first front lens-element group, a second lens-element group, a third lens-element group, a fourth lens-element group, and a fifth back lens-element group is arranged in a stationary manner. Relative to an imaging plane in a lens barrel and both the focusing front group and the focusing back group are movable jointly relative to one another and to the lens-element groups arranged in a stationary manner in order to focus the lens on objects at different object distances.

Abstract: A lens with a fixed focal length comprising including a first front lens-element group, a second lens-element group, a third lens-element group, a fourth lens-element group, and a fifth back lens-element group. Relative to an imaging plane in a lens barrel and both the focusing front group and the focusing back group are movable jointly relative to one another and to the lens-element groups arranged in a stationary manner in order to focus the lens on objects at different object distances. The front lens-element group has a positive refractive power and the central group and the back lens-element group have a negative refractive power.

Abstract: The invention describes a focal length extender for a telescopic imaging system with interchangeable viewing eyepieces, including a cylindrical housing, which has a first and a second stop plane which are perpendicular to its cylinder axis in the direction of the light with associated connecting elements to the telescope body and for interchangeable viewing eyepieces and in which the housing has a relay lens arranged between the first stop plane and the second stop plane, wherein the relay lens is divided in two and consists of a first positive, neutral or negative lens element and a further negative lens element, wherein between the first and the further lens element, a beam splitter surface is arranged downstream at an angle to the optical axis of the imaging system and the first and further lens element together with the distance therebetween has an overall negative refractive power.

Abstract: A photo adapter for attaching to the eyepiece of an optical magnification device having a diopter compensation apparatus, equipped with an apparatus for compensating the diopter compensation.

Abstract: The invention describes a focal length extender for a telescopic imaging system with interchangeable viewing eyepieces, including a cylindrical housing, which has a first and a second stop plane which are perpendicular to its cylinder axis in the direction of the light with associated connecting elements to the telescope body and for interchangeable viewing eyepieces and in which the housing has a relay lens arranged between the first stop plane and the second stop plane, wherein the relay lens is divided in two and consists of a first positive, neutral or negative lens element and a further negative lens element, wherein between the first and the further lens element, a beam splitter surface is arranged downstream at an angle to the optical axis of the imaging system and the first and further lens element together with the distance therebetween has an overall negative refractive power.

Abstract: An apparatus for illuminating a marking, which is applied on a transparent reticle in the form of a diffraction structure, wherein illuminating beams are injected into the reticle via a side edge surface of the reticle such that they are emitted after diffraction at the marking perpendicular to the plane of the reticle, wherein a concavely curved mirror having two focal points is attached to the side edge surface such that a light source is arranged in the region of the first focal point and the marking is arranged in the region of the second focal point, wherein a second mirror having two focal points is attached such that a second light source with a second emission wavelength is arranged in the first focal point thereof and the marking is arranged in the region of the second focal point of the second mirror.

Abstract: An apparatus for illuminating a marking, which is applied on a transparent reticle in the form of a diffraction structure, wherein illuminating beams are injected into the reticle via a side edge surface of the reticle such that they are emitted after diffraction at the marking perpendicular to the plane of the reticle, wherein a concavely curved mirror having two focal points is attached to the side edge surface such that a light source is arranged in the region of the first focal point and the marking is arranged in the region of the second focal point, wherein a second mirror having two focal points is attached such that a second light source with a second emission wavelength is arranged in the first focal point thereof and the marking is arranged in the region of the second focal point of the second mirror.

Abstract: A description is given of a telescopic sight with variable magnification, comprising a fixed objective and first image plane assigned thereto, a variable system with second image plane assigned thereto, and a fixed eyepiece for viewing the second image plane and that has a stop in the vicinity of the first image plane whose aperture diameter can be varied as a function of the magnification of the variable system in order to suppress scattered and/or false light.

Abstract: A description is given of a telescopic sight with variable magnification, comprising a fixed objective and first image plane assigned thereto, a variable system with second image plane assigned thereto, and a fixed eyepiece for viewing the second image plane and that has a stop in the vicinity of the first image plane whose aperture diameter can be varied as a function of the magnification of the variable system in order to suppress scattered and/or false light.

Abstract: A monocular or binocular optical system that is capable of automatically adjusting a diopter setting upon or during a change in magnification in a way that acts to preserve focus and a corresponding method for adjusting a diopter setting to preserve focus upon or during a change in magnification.

Abstract: A telescope comprising a lens (3) and a focussing member (5) which can be displaced by means or a focussing adjustment ring (12), whereby the basic position thereof can be adjusted by a lockable diopter adjustment ring (13), also comprising a reversing system (4) and an eyepiece (6), characterised in that a cam disk (20) for displacement of the focusing member (5) is associated with the diopter adjustment ring (13) when the eyepiece (6, 7, 8) is used with modifiable enlargement, whereby said cam disk (20) can be displaced by a value which is dependent upon the diopter adjustment and modification of the enlargement of the eyepiece.