Abstract: The present disclosure is directed to an optical system internally having an intermediate imaging position that is conjugated to a magnification conjugate point on a magnification side and a reduction conjugate point on a reduction side, respectively, the optical system including: a magnification optical system having A (A is an integer of three or more) pieces of lens elements, positioned on the magnification side with respect to the intermediate imaging position; and a relay optical system having B (B is an integer of two or more) pieces of lens elements, positioned on the reduction side with respect to the intermediate imaging position. A first lens group composed of ? pieces (? is one or more and less than B) of lens elements positioned first from the magnification side in the relay optical system has a negative power.

Abstract: A zoom lens including, in order from object side to image side, first to fourth lens units respectively having positive, negative, positive, and positive refractive powers. During zooming from a wide-angle end to a telephoto end, the first lens unit is arranged to move, the distance between the first lens unit and the second lens unit increases, the distance between the second lens unit and the third lens unit decreases, and the distance between the third lens unit and the fourth lens unit decreases. The second lens unit consists of a first lens having a negative refractive power and a second lens having a positive refractive power, the second lens being disposed on the image side of the first lens. A predetermined condition is satisfied.

Abstract: A mirror assembly can include a housing, a mirror, and a light source. In certain embodiments, the mirror includes a light pipe configured to emit a substantially constant amount of light along a periphery of the mirror. In some embodiments, the mirror assembly includes a sensor assembly. The sensor assembly can be configured to adjust the amount of emitted light based on the position of a user in relation to the mirror. Certain embodiments of the mirror include an algorithm to adjust light based on the position of a user relative to the mirror, the level of ambient light, and/or the activation of different light modes.

Abstract: Light re-reflection in a picture generation unit for a heads up display is reduced by a housing having walls that are “surfaced” to have inclined surfaces, which reflect light incident upon them toward inclined surfaces on a second and opposing surfaced wall. Re-reflections of light off the surfaced sidewalls attenuates light to a degree that it cannot generate a visible image.

Abstract: An imaging optical system consists of a first lens group and a second lens group, in order from a magnification side along an optical axis, an intermediate image is formed between the first lens group and the second lens group on the optical axis, at least one of the first lens group or the second lens group includes a reflector that bends the optical axis, the second lens group includes a movable lens group that moves during zooming, and predetermined conditional expressions are satisfied.

Abstract: A projection optical system that enlarges an image to be displayed on an image display surface to an angle of view of 70 degrees or more, projects the enlarged image, and includes: a fixed focal length lens that has, in order from an enlargement side, a first optical system and a second optical system on a same optical axis, wherein the second optical system forms an intermediate image of the image, the first optical system enlarges and projects the intermediate image, the projection optical system comprises positive lenses that are positioned on both of the enlargement side and a reduction side of the intermediate image and are adjacent to each other, and following conditional expressions are satisfied: 0.4<Tm1/Tw<0.7 and T12w/Tw<0.2 (2).

Abstract: A microlithographic projection exposure apparatus optical 22 system includes a first reflective surface and at least one second reflective surface, each in the optical beam path. The first reflective surface is movable for the correction of an aberration that occurs during the operation of the optical system. The optical system is configured in so that, during the travel movement of the first reflective surface, the relative position of the first reflective surface and of the second reflective surface is maintainable in a stable manner. Either the first reflective surface and the second reflective surface directly succeed one another in the optical beam path, or there are only reflective optical elements between the first reflective surface and the second reflective surface.

Abstract: An imaging device, an imaging apparatus, and an electronic device for imaging are disclosed. The imaging device includes an imaging sensor that operatively captures an image along an optical axis. The imaging device also includes a lens assembly, and the lens assembly includes a first lens and a second lens. The first lens and the second lens at least partially overlap each other in a first direction parallel to the optical axis. The lens holder operatively adjusts a relative arrangement between the first and second lens to focus the image on the imaging sensor.

Abstract: The invention relates to a device (102) for optical beam expansion of an optical system having a guide tube (220), a first guide cylinder (222) having a first lens (226), wherein the first guide cylinder (202) is arranged within the guide tube (220) so as to be displaceable along the longitudinal axis of the guide tube (220), and a second guide cylinder (224) having a second lens (228), wherein the second guide cylinder (224) is arranged within the guide tube (220) so as to be displaceable along the longitudinal axis of the guide tube (220). A first displacement device is provided to displace the first guide cylinder (222) along the longitudinal axis (340) of the guide tube (220), and a second displacement device is provided to displace the second guide cylinder (224) along the longitudinal axis of the guide tube (220).

Abstract: A laser processing machine includes a beam parameter product variable device, and a beam diameter variable device. The beam parameter product variable device sets beam parameter products of a laser beam to a predetermined value. The beam diameter variable device includes a first lens that is movable in an optical axis direction and having a positive focal length, and converts divergent light of a laser beam emitted from an emission end of the laser beam into convergent light, and a second lens that is movable in the optical axis direction and having a negative focal length on which the convergent light is incident. A third lens having a positive focal length, focuses the laser beam emitted from the beam diameter variable device, and irradiates a plate material with the focused laser beam.

Abstract: A projection optical system includes a first lens unit adapted to make a enlargement-side imaging surface and an intermediate image conjugate with each other, a second lens unit adapted to make the intermediate image and a reduction-side imaging surface conjugate with each other. The first lens unit has positive power, and the second lens unit has negative power. Defining a focal distance of the first lens unit as fU1, a focal distance of the second lens unit as fU2, a total lens length of the first lens unit as LLU1, and a total lens length of the second lens unit as LLU2, the following expression (1) and expression (2) are satisfied: ?0.3<fU1/fU2<?0.005??(1) 0.5<LLU1/LLU2<0.9??(2).

Abstract: A projection system that can be incorporated in a projector includes a first lens unit that makes a screen (enlargement-side image formation plane), which is located on the enlargement-side, conjugate with an intermediate image and a second lens unit that makes the intermediate image conjugate with a reduction-side image formation plane, which is located on the reduction side. The first lens unit has positive power, and the second lens unit has negative power. A second-lens-unit intermediate-image-side first lens, which is provided in the second lens unit and closest to the intermediate image, has positive power. The following expression is satisfied: ?0.3?fU1/fU2<0 where fU1 denotes the focal length of the first lens unit, and fU2 denotes the focal length of the second lens unit.

Abstract: The zoom lens forms an intermediate image at a position conjugate to a reduction side imaging plane and forms the intermediate image again on a magnification side imaging plane. The zoom lens includes: a first optical system on the magnification side; and a second optical system on the reduction side. The intermediate image is formed between the magnification and reduction sides. The second optical system includes two or more movable lens groups, which move by changing spacings between the groups adjacent to each other in a direction of an optical axis during zooming, and one or more stationary lens groups which remain stationary with respect to the reduction side imaging plane during zooming. Also, the movable lens groups are disposed to be adjacent to both the magnification side and the reduction side of the stationary lens group closest to the magnification side in the second optical system.

Abstract: The zoom lens includes: a first optical system on a magnification side; and a second optical system on a reduction side in a state where the intermediate image is formed between the magnification side and the reduction side. The second optical system includes, in order from the magnification side, a second-1 lens group which has a positive refractive power, a second-2 lens group which has a positive refractive power, and a second-3 lens group which has a positive refractive power. The second-1 lens group and the second-2 lens group move in directions opposite to each other while changing spacings between the groups adjacent to each other in a direction of an optical axis during zooming. The second-3 lens group remains stationary with respect to the reduction side imaging plane during zooming. In addition, the zoom lens satisfies a predetermined conditional expression (1).

Abstract: Provided is an eyepiece lens to be used for observing an image displayed on an image displaying surface, the eyepiece lens consisting of, in order from the image displaying surface side to an observation side: a first lens unit having a negative refractive power; and a second lens unit having a positive refractive power. The first lens unit consists of one negative lens, and the second lens unit consists of, in order from the image displaying surface side to the observation side, a positive lens and a negative lens that has a concave surface facing the observation side. During adjustment of a diopter, the first lens unit is configured to not move, and the second lens unit is configured to move.

Abstract: A finder optical system includes an image inverter optical member and an eyepiece lens system. The eyepiece lens system includes a negative first lens element, a positive biconvex second lens element, and a meniscus third lens element having a concave surface on the eyepoint side, in that order from the object side. A diopter adjustment operation is performed by moving the second lens element along the optical axis. Conditions (1) and (2) are satisfied: ?0.2<f/f3<0.2??(1), and 2.15<f(L3n?1)/L3b<3.00??(2), wherein f designates the focal length of the entire the eyepiece lens system at a diopter of ?1, f3 designates the focal length of the third lens element, L3n designates the refractive index at the d-line of the third lens element, and L3b designates the radius of curvature of the surface on the eyepoint side of the third lens element.

Abstract: The invention proposes a short-distance front projection system, that is to say with a wide angle, occupying a small volume and offering a possibility of focusing as well a zoom function. It makes it possible to obtain images with a diagonal greater than 2 meters, the whole of the optical system being at least 50 cm from the plane of the image. This projector is constructed on the basis of three optical elements: an ocular, an afocal lens system and a final group forming an objective intended to form the intermediate image in front of the mirror.

Abstract: A zoom lens system includes: a primary image forming lens group that forms light from an object side into an intermediate image and a relay lens group that forms light from the intermediate image into a final image. The primary image forming lens group includes, in order from the object side, a first fixed lens group G1 with negative refractive power, a stop St, and a second fixed lens group G2 with positive refractive power, and the relay lens group includes, in order from the object side, a third fixed lens group G3 with negative refractive power, a first moving lens group G4 with positive refractive power, and a second moving lens group G5 with positive refractive power.

Abstract: The present invention relates to a device for adjusting an optical magnification of a microscope, the device including: a magnification adjuster adapted to change the optical magnification of the microscope in accordance with the relative rotation position with respect to a tube unit; a membrane potentiometer positioned on the rotating passage of the magnification adjuster to output an electrical signal corresponding to the contacted position of the magnification adjuster therewith; and a controller adapted to receive the electrical signal outputted from the membrane potentiometer to output the optical magnification corresponding to the rotated position of the magnification adjuster.

Abstract: Observation over a superwide field of view is possible with a short, lightweight, and inexpensive eyepiece optical system and a binocular barrel. A microscope optical system includes an objective optical system configured to collect light from a specimen; an imaging optical system configured to image the light coming from the specimen and collected by the objective optical system; and an eyepiece optical system configured to magnify the image of the specimen formed by the imaging optical system and form a virtual image in an eye of an observer, wherein the following conditional expressions are satisfied, M=Fntl/Fob×250/Fne??(1) Fntl=Ftl×Kt??(2) Fne=Fe×Kt??(3) 0.4<kt<0.95??(4).

Abstract: Example embodiments of a large dynamic range sequential wavefront sensor for vision correction or assessment procedures are disclosed. An example embodiment includes first and second optically coupled 4F relays and a variable focus lens disposed substantially at the image plane of the first 4F relay and the object plane of the second 4F relay.

Abstract: Provided are an ocular zoom optical system which has a wide apparent field of view even on a low power side and in which aberrations are favorably corrected while a sufficient eye relief is secured over the entire zoom range, and an optical instrument including the ocular zoom optical system. The ocular zoom optical system 3 includes, in order from the object side: a first lens group G1 having a negative refractive power; a second lens group G2 having a positive refractive power; and a third lens group G3 having a positive refractive power and at least one aspheric surface. An intermediate image I? is formed between the first lens group G1 and the second lens group G2. During zooming, the third lens group G3 is fixed on the optical axis, and the first lens group G1 and the second lens group G2 are moved in directions opposite to each other with the intermediate image I? interposed therebetween.

Abstract: A large aperture zoom optical system and an image pickup apparatus have a five-lens-group arrangement of positive-negative-positive-negative-positive refractive powers. At the time of zooming, the fifth lens group is fixed, and at least the second lens group, the third lens group and the fourth lens group are moved. The third lens group for use in focusing is composed of a single lens element.

Abstract: Provided is an inverted microscope 1 comprising an objective optical system 2 that collects light from a specimen A; an image-forming optical system 3 that images the light from the specimen A that has been collected by the objective optical system 2 to form an intermediate image; a relay optical system 6 that relays the intermediate image B of the specimen A formed by the image-forming optical system 3; a binocular lens barrel 5 that splits the light from the relay optical system 6; a pair of ocular optical systems 4 that image, in a magnified manner, the intermediate images that have been split by the binocular lens barrel 5 on eyes E of an observer as virtual images; wherein the following conditional expressions are satisfied: K=(Fntl/Ftl)×?RL??(1), Fne=Fe×K??(2), and 0.3<K<0.9??(3).

Abstract: A microscope system and observation control method. An electric zoom consecutively changes a magnification for a sample. A revolver includes a plurality of objective lenses of different magnifications and switches the objective lens placed in an observation optical path to intermittently change the magnification for the sample. A control section calculates a total magnification at which the sample is observed based on a magnification provided by the electric zoom and the magnification of the objective lens currently placed in the observation optical path. The control section operates when the revolver switches the objective lens placed in the observation optical path, to determine a target magnification that is the magnification of the electric zoom required to keep the total magnification obtained after the switching of the objective lens equal to the total magnification obtained before the switching of the objective lens.

Abstract: A beam shaping unit for focusing a divergent laser beam includes a first optical element to receive the laser beam, a second optical element to receive the beam from the first optical element, an optical focusing unit to receive the beam from the second optical element, a first focal point adjustment device coupled to the first optical element, the first focal point adjustment device being configured to adjust the beam focal point diameter by manipulating the first optical element, and a second focal point adjustment device coupled to the second optical element, the second focal point adjustment device being configured to adjust, in the beam propagation direction, the beam focal position by manipulating the second optical element, and in which the beam shaping unit is configured to image the beam from the first optical element through an intermediate focal point onto the second optical element.

Abstract: Liquid lens cells are used in a compound variable power optical system that forms an intermediate image between the object and the final image. A first variable power optical component is located between the object and an intermediate real image. The first variable power optical component varies power to change the magnification of the intermediate real image. A second variable power optical component is located between the intermediate real image and the final image. The second variable power optical component varies power to change the magnification of the final image. At least one of the first and second variable power optical components is stationary on the optical axis and comprises at least two liquids with different refractive properties and at least one variable shape contact surface between the two liquids, with variations in the shape of the contact surface producing a change of optical power in the optical system.

Abstract: A light source arrangement (101) for an illumination device of a medical-optical observation apparatus has an illumination light source (7) and an illumination optical unit (15) for illuminating an observation object (23) with illumination light from the illumination light source (7). The light source arrangement (101) has at least one luminescence emitter (3) as light source and an imaging optical unit (105) that generates an image (7) of the at least one luminescence emitter (3) with a defined magnification scale, which image forms the illumination light source for the illumination device.

Abstract: An optical system incorporating a compact internal field of view switch configured to switch the field of view of the optical system between a narrow field of view and a wide field of view while maintaining a constant exit aperture size. In one example the optical system includes an active imaging sub-system optically coupled to the exit aperture, and the field of view switch is positioned between the exit aperture and the active imaging sub-system. In one example the field of view switch is configured as a pupil relay having non-unity magnification.

Abstract: A sighting apparatus for displaying compensation position is described. The sighting apparatus includes a magnification adjustment module; a magnification generation module, which comprises a magnification pattern for undergoing a movement of the magnification pattern, and a sensing unit for detecting the magnification pattern to obtain a current magnification value; a display unit, for displaying the target in a reference position of the displaying unit when the sighting apparatus sights the target; and a controller coupled to the magnification generation module and the display unit respectively, for acquiring a first compensation position based on a range distance of the target, and for computing a ratio of the current magnification value and a predetermined magnification value of the sighting apparatus, wherein the controller generates a second compensation position based on the first compensation position and the ratio for displaying the second compensation position in the display unit.

Abstract: A light modulation device side lens group has different powers in the longitudinal direction and the lateral direction of a liquid crystal panel. Therefore, as the entire system of the optical projection system, the light modulation device side lens group has different magnification in the longitudinal and lateral directions. Therefore, it is possible to make the aspect ratio of an image of the liquid crystal panel different from the aspect ratio of an image projected on a screen. That is, conversion can be performed on an aspect ratio. At this time, a distance p between each focus or a diaphragm and the screen SC side end surface of the light modulation device side lens group satisfies the conditional expressions, so it is possible to achieve a predetermined or higher telecentricity in both states, that is, a first operating state and a second operating state.

Abstract: A beam shaping unit for focusing a divergent laser beam includes a first optical element to receive the laser beam, a second optical element to receive the beam from the first optical element, an optical focusing unit to receive the beam from the second optical element, a first focal point adjustment device coupled to the first optical element, the first focal point adjustment device being configured to adjust the beam focal point diameter by manipulating the first optical element, and a second focal point adjustment device coupled to the second optical element, the second focal point adjustment device being configured to adjust, in the beam propagation direction, the beam focal position by manipulating the second optical element, and in which the beam shaping unit is configured to image the beam from the first optical element through an intermediate focal point onto the second optical element.

Abstract: A relay zoom system includes, in order from an object side, a first lens group having a positive refractive power and a second lens group having a positive refractive power. Furthermore, in the relay zoom system, the first lens group and the second lens group are each made up of at least two positive lenses and one negative lens. The first lens group and the second lens group in the relay zoom system are configured so as to move along an optical axis when magnification is varied from a lower magnification edge state to a higher magnification edge state.

Abstract: A real-image variable-magnification viewfinder substantially consists of, in order from the object side: an objective lens system substantially consisting of a positive first lens, a negative second lens, a positive third lens, and a positive fourth lens; an erect optical system formed by a plurality of optical members; and a positive eyepiece lens system. The first lens and the third lens are fixed relative to the optical axis direction during magnification change, and the second lens and the fourth lens are moved in the optical axis direction during magnification change. All optical surfaces of all the optical members forming the erect optical system are planar surfaces. At least one of the optical members forming the erect optical system is made of a glass material. A predetermined conditional expression is satisfied.

Abstract: A zoom viewfinder substantially consists of, in order from the object side: a variable-magnification objective lens system substantially consisting of a first lens group that includes a negative first-group first lens and a reflective member arranged in this order from the object side, a positive second lens group that is moved during magnification change, and a positive third lens group that is moved during magnification change; an erect optical system having a reflective surface for converting an inverted image into an erect image; and a positive eyepiece lens system, wherein conditional expressions (1), (2A) and (3) below are satisfied: 1.5<U2/U1<3.0??(1), 1.76?|f2/f|<2.0??(2A) and 1.0<f3/f2<5.0??(3).

Abstract: A reticle system for a variable optical power sighting device includes front and rear reticles proximate respective front and rear focal planes of the device. Range-compensating features are provided, such as a scale and a pair of bracketing marks formed in the rear reticle which cooperate with an indicator mark formed in the front reticle. The indicator mark is radially offset from the optical axis it appears to move in the field of view along the scale in response to adjustment of the optical power to thereby indicate a measurement corresponding to a size of a distant target subtended in the field of view by the bracketing marks. A two-part electronic reticle system is also disclosed utilizing similar principles of operation. The rear reticle and scale may be electroformed to reduce cost and improve light transmission relative to a glass reticle.

Abstract: An optical system for generating an image of an object is provided. It has at least one objective, at least one lens erecting system and at least one eyepiece. The objective, the lens erecting system and the eyepiece are arranged along an optical axis of the optical system. The lens erecting system is arranged between the objective and the eyepiece. The objective has at least two optical units which, for magnifying the image, are configured to be displaceable along the optical axis.

Abstract: An objective changer having incident-light illumination for light microscopes, including: at least two microscope objectives for examining a specimen, a movable carrier, on which the microscope objectives are mounted, an immovable carrier, which is adapted for mounting on a base body of the microscope, wherein the movable carrier is adapted for defined positioning thereof relatively to the immovable carrier, and at least one illuminating means for illuminating the specimen. The objective changer includes at least one transfer interface for transferring energy for illuminating the specimen is provided on the immovable carrier, at least one energy connector, which is rigidly connected to the movable carrier, is provided for receiving energy to illuminate the specimen, the energy connector is connected to an illuminating means, and by positioning the movable carrier relatively to the immovable carrier, a line engagement can be established between the transfer interface and an energy connector.

Abstract: Wide-angle, deep-field, close-focusing optical systems are disclosed. According to one aspect, the optical system comprises a negative lens unit and a relay lens. The negative lens unit accepts radiation from an object in space. The relay lens is coupled to the negative lens unit. The negative lens unit and the relay lens are aligned on an optical axis in that order. The negative lens unit forms a first image on the relay lens to form a final image at a final image plane at a distance from the relay lens. The relay lens may comprise a zoom lens or zoom lens components, which may be movable.

Abstract: A sighting apparatus for displaying a magnification value is described. The sighting apparatus includes a magnification generation module, a controller and a display unit. The magnification generation module includes a magnification pattern, which has a plurality of magnification values, and a sensing unit. When the magnification pattern is rotated, the sensing unit detects one of the magnification values from the magnification pattern. The magnification generation module generates a magnification signal corresponding to the magnification value. The controller transforms the magnification signal and the display unit displays the magnification value corresponding to the magnification signal.

Abstract: Provided is a head-mounted display element, including: a first casing (11) which incorporates therein at least a display element (21), and has a light projection window (11a) for projecting image light from the display element (21); a second casing (12) which incorporates therein an eyepiece optical system (31) with a refractive power, and has a light receiving window (12a) for receiving incident image light projected through the light projection window (11a) and an eyepiece window (12b) for emitting the image light that has passed through the eyepiece optical system (31); and a coupling portion (13) for coupling the second casing (12) to the first casing (11) so as to make adjustable a length of an optical path between the light projection window (11a) and the light receiving window (12a).

Abstract: A multi-magnification viewing and aiming scope includes a first imaging group including an objective lens and an eyepiece lens lying on the optical path. The first imaging group forms a first image having a first magnification on the optical path at an image location. A second imaging lens group is controllably inserted into the optical path between at least some elements of the objective lens and the eyepiece lens. Upon insertion of the second imaging lens group into the optical path an optical combination of the first imaging group and the second imaging lens group forms a second image having a second magnification on the optical path at substantially the image location. The insertion may be accomplished by a tumbler mechanism upon which the second imaging lens group is mounted for pivoting the second imaging lens group about an axis perpendicular to the optical path.

Abstract: A portable magnifying instrument useful for colposcopy is provided which may include in combination an optical system capable of providing a distortion free clear continuously varying 10× to 15× magnification of a three-dimensional wide object; an integrated energy efficient, low powered and intensity controlled illumination system; a power pack and mounting. The optical system may have an eyepiece lens system and an objective lens system. The illumination system may have a plurality of light emitting diodes (LEDs) connected to the power pack; mounted in such a manner that the angle between the LEDs is maintained with respect to the optical axis of the lens system and that the light beam from the said LEDs impinges on the wide object to be observed at the focus of the said lens system.

Abstract: A beam shaping unit for focusing a divergent laser beam includes a first optical element to receive the laser beam, a second optical element to receive the beam from the first optical element, an optical focusing unit to receive the beam from the second optical element, a first focal point adjustment device coupled to the first optical element, the first focal point adjustment device being configured to adjust the beam focal point diameter by manipulating the first optical element, and a second focal point adjustment device coupled to the second optical element, the second focal point adjustment device being configured to adjust, in the beam propagation direction, the beam focal position by manipulating the second optical element, and in which the beam shaping unit is configured to image the beam from the first optical element through an intermediate focal point onto the second optical element.

Abstract: An object of interest is illuminated within the field of view of a microscope objective lens located to receive light passing through the object of interest. Light transmitted through the microscope objective lens impinges upon a variable power element. The variable power element is driven with respect to the microscope objective lens to scan through multiple focal planes in the object of interest. Light transmitted from the variable power element is sensed by a sensing element or array.

Abstract: The invention relates to a light source optical system for endoscopes which is compatible with various viewing modes, prevents an associated light source apparatus from growing bulky, and makes sure brightness. The light source optical system comprises, in order from the light source 1, the collective optical system 2 for collecting light from the light source, the magnification conversion optical system 3 for reducing a pupil magnification, and the positive lens group 4 for collecting light from the magnification conversion optical system 3, and satisfies Condition (1) with respect to the principal point-to-point distance d of the collective optical system 2 and magnification conversion optical system 3, the rear focal length f2B of the collective optical system 2 and the front focal length f3F of the magnification conversion optical system 3.

Abstract: An optical system is described herein which has a compact, all reflective design that has multiple fields of view for imaging an object. The optical system also has identical viewing directions and can have several different configurations for adding laser range finding and designating components.

Abstract: An optical system includes a dynamically focused lens that variably changes focal length to focus light on a material under evaluation at discrete axial depths, and a scanning element that laterally scans the material to focus light on the material at points that are laterally adjacent the axial depth.

Abstract: Provided is a projection optical system for an ultra-short focus image projection device. The disclosed projection optical system includes a first optical system for zooming an image formed by an image display device to form a first intermediate image, a second optical system for enlarging the first intermediate image to form a second intermediate image, and a reflection optical system for reflecting light which forms the second intermediate image. An optical axis of the first optical system translates parallel with respect to an optical axis of the second optical system in a direction perpendicular to the optical axis of the first optical system.

Abstract: Large aperture optical systems that are extremely well corrected over a large flat field and over a large spectral range are disclosed. Breathing and aberration variation during focusing are optionally controlled by moving at least two groups of lens elements independently. Aberration correction in general is aided by allowing the working distance to become short relative to the format diagonal. Field curvature is largely corrected by a steeply curved concave surface relatively close to the image plane. This allows the main collective elements to be made of low-index anomalous dispersion materials in order to correct secondary spectrum. In wide-angle example embodiments, distortion may be controlled with an aspheric surface near the front of the lens.