Abstract: A zoom lens system is disclosed. The zoom lens system forms a final image of an object and a first intermediate real image between the object and the final image. The zoom lens system includes a first optical unit located between the object and the first intermediate real image. The first optical unit comprises at least one optical subunit which is moved to change the size (magnification) of the first intermediate real image. The zoom lens system also includes a second optical unit located between the first intermediate real image and the final image, at least a portion of which is moved to change the size (magnification) of the final image. The zoom lens system provides a wide zoom range of focal lengths with continuous zooming between the focal lengths.

Abstract: A zoom lens system is disclosed. The zoom lens system forms a final image of an object and a first intermediate real image between the object and the final image. The zoom lens system includes a first optical unit located between the object and the first intermediate real image. The first optical unit comprises at least one optical subunit which is moved to change the size (magnification) of the first intermediate real image. The zoom lens system also includes a second optical unit located between the first intermediate real image and the final image, at least a portion of which is moved to change the size (magnification) of the final image. The zoom lens system provides a wide zoom range of focal lengths with continuous zooming between the focal lengths and optional image stabilization.

Abstract: An anamorphic imaging system is disclosed which maximizes the use of available image area to minimize display magnification and image degradation due to display magnification, reduces the amount of anamorphic squeeze or stretch during photography to lower image degradation due to anamorphosis, and in film applications, utilizes a film frame that is only three perforations in height to reduce the amount of original film needed. The frame for either film or digital applications has an aspect ratio of approximately 16:9, is contained within the total available frame area of a three-perforation frame or digital imager, and is sized to maximize image area. In preferred embodiments, the image capture area is approximately 0.900 inches wide by approximately 0.506 inches tall.

Abstract: A zoom lens system is disclosed. The zoom lens system forms a final image of an object and a first intermediate real image between the object and the final image. The zoom lens system includes a first optical unit located between the object and the first intermediate real image. The first optical unit comprises at least one optical subunit which is moved to change the size (magnification) of the first intermediate real image. The zoom lens system also includes a second optical unit located between the first intermediate real image and the final image, at least a portion of which is moved to change the size (magnification) of the final image. The zoom lens system provides a wide zoom range of focal lengths with continuous zooming between the focal lengths and optional image stabilization.

Abstract: A zoom lens system is disclosed. The zoom lens system forms a final image of an object and a first intermediate real image between the object and the final image. The zoom lens system includes a first optical unit located between the object and the first intermediate real image. The first optical unit comprises at least one optical subunit which is moved to change the size (magnification) of the first intermediate real image. The zoom lens system also includes a second optical unit located between the first intermediate real image and the final image, at least a portion of which is moved to change the size (magnification) of the final image. The zoom lens system provides a wide zoom range of focal lengths with continuous zooming between the focal lengths and optional image stabilization.

Abstract: A viewfinder eyepiece for a camera having a video signal tap, particularly a professional high definition video camera, for viewing the display screen of a display device, such as a CRT, in the viewfinder. The eyepiece includes a negative powered lens on an optical axis and positioned adjacent the display screen, a first positive powered lens on the optical axis is spaced from the negative powered lens is located at an eye-viewing end of the eyepiece, and a second positive powered lens positioned on the optical axis between the negative powered lens and the first positive powered lens. The second positive lens is mounted in the eyepiece to be movable along the optical axis in the space between the negative powered lens and the first positive powered lens for adjusting the focus on the display screen through the eyepiece.

Abstract: A viewfinder eyepiece for a camera having a video signal tap, particularly a professional high definition video camera, for viewing the display screen of a display device, such as a CRT, in the viewfinder. The eyepiece includes a negative powered lens on an optical axis and positioned adjacent the display screen, a first positive powered lens on the optical axis is spaced from the negative powered lens is located at an eye-viewing end of the eyepiece, and a second positive powered lens positioned on the optical axis between the negative powered lens and the first positive powered lens. The second positive lens is mounted in the eyepiece to be movable along the optical axis in the space between the negative powered lens and the first positive powered lens for adjusting the focus on the display screen through the eyepiece.

Abstract: An adjustable viewfinder optical system for a shoulder-supported movie or video camera having interchangeable objective lenses. The system includes first and second lens groups aligned on an optical axis for receiving and relaying an image received from the objective lens of the camera to the viewer's eye. The first lens group is in a forwardly extending portion of the viewfinder that is pivotally joined to a rearwardly extending portion of the viewfinder containing the second lens group. The forwardly extending portion has a telescoping portion for varying the eye position of the viewer relative to the camera in the fore-and aft direction. The light is collimated between the first and second lens groups at the telescoping portion, whereby the image viewed in the viewfinder remains in focus and the same magnification throughout the telescoping adjustment movement.

Abstract: A thermal compensation system for an optical lens that has a focus adjustment with visible focus distance numerals and a juxtaposed index line for identifying the focus distance. The index line is provided on an internal ring slidably mounted to rotate circumferentially with respect to a barrel portion of the optical lens that includes the focus distance numerals. An actuator mounted within the optical lens includes a wax motor that is responsive to temperature changes and mechanical lever that engages both the wax motor and the ring for causing circumferential movement of a ring in response to actuation movement of the wax motor as caused by temperature changes. Further, an adjustment cam is provided for adjusting the relative positions of the wax motor and lever for calibrating the temperature responsive movements of the ring bearing the index line.

Abstract: A high performance zoom lens system formed by multiple focus lens groups, multiple zoom lens groups and single auxiliary lens group aligned in that order on a common optical axis and arranged to collect radiation emanating from an object space and deliver that radiation to an axially stationary real image in an image space, such as on a film plane or video CCD. The multiple focus lens groups comprise a first focus lens group of negative optical power that is axially movable and contains at least one non-spherical, non-plano, optically refractive surface, and a second focus lens group of positive optical power that is axially movable. The multiple zoom lens groups comprise a first zoom lens group of negative optical power that is axially movable, and a second zoom lens group of positive optical power that is axially movable and contains an optical stop or iris.

Abstract: A variable length telescoping viewfinder for cameras that provides a variably adjustable eye viewing distance relative to the camera without changing the focus or magnification of the scene being photographed throughout the telescoping movement of the viewfinder. The light rays of the real image supplied to the viewfinder directly or indirectly from the camera are passed through a field lens, Pechan prism, relay lens system forming collimated light rays from the fixed front module to the movable rear module wherein lens elements form an intermediate image that is viewed through an eyepiece lens group. The front module is weakly powered and of a substantial effective optical length because of the inclusion of the Pechan prism. The image forming lens group of the rear module is weakly powered whereby relative telescopic movement between the front and rear modules does not adversely affect the location, focus or magnification of the intermediate image throughout the range of movement.

Abstract: A video monitoring system for a movie film camera usable with either spherical or anamorphic lenses wherein conventional, unmodified video monitors and recorders may be used. A video camera is positioned in the film camera to receive an image directly from the camera lens without interposing either a ground glass for imaging or an optical deanamorphosing lens. The anamorphic image, which is horizontally squeezed (such as by a factor of 2), that is received by the video camera then is electronically processed to deanamorphose the image by producing an analog video signal to a video monitor that displays the properly proportioned image in the middle one-half of the monitor screen and produces black areas or strips across the top one quarter and bottom one quarter of the screen. The horizontal lines of the video picture are electronically interpolated for enhancing the picture.

Abstract: A high performance, large aperture, long focal length visible waveband objective lens system (60) comprises a telephoto objective lens group (48) spaced from a focusing lens group (49) and an auxiliary lens group (54), all supported in a support assembly (43) of fixed length. The lens groups are aligned on a common optical axis (40) and arranged to form a real image (34) in image space (42) from radiation entering the system (60) from a real object in object space (41). The telephoto objective lens group (48) is stationary and comprises a positively powered lens element (A) and a negatively powered lens sub-group (50) containing a quintuplet lens group (51) with lens elements (B, C, D, E, F) and a lens element (G).

Abstract: A forward looking infrared optical system comprises a refractor telescope 20 in combination with a powered window and fold mirror arrangement 30. Arrangement 30 comprises a powered window element J with concentric spherical refractive surfaces having their common center of curvature on the common optical axis 19 where the latter is folded by the reflective surface 27 of the mirror element I. Because the window element J is powered it introduces significant spherical aberration and some color aberration to the system however telescope 20 provides compensation for such aberrations by being non-afocal and non-diffraction limited. This is achieved by the objective system 21 of the telescope 20 being telephoto and formed of two elements H,G of which H is positively powered and G is negatively powered and color corrective. The refractive surfaces of element G are each spherical whereas at least one refractive surface (15) of element H is aspheric.

Abstract: An infrared afocal refractor telescope (40) comprises a zoom system (27), a collecting system (28) and an eyepiece system (30) arranged in a common optical axis (26). The zoom system (27) is formed by a fixed objective lens component (K) and by a first lens component (H) mounted on a carriage (32) and by a second lens component (I,J) mounted on a carriage (31), the carriages (32,31) being separately movable along the optical axis (26). The movable lens components of the zoom system (27) each have the same sign of optical power and the variation in telescope magnification provided by selective positioning of the carriages (32,31) is at least 5:1 in range. The locus (34,33) of movement of each of the two movable lens components (H;I,J) renders the telescope athermalized.

Abstract: An infrared objective lens assembly comprises a four-component zoom system (25) which accepts from object space (22) radiation in the infrared waveband, and a one-component collecting system (26) which forms a real image (24) of that radiation. The components of the zoom (25) and collecting (26) systems are formed by lens elements (D,E,F,G,H,I) such that with respect to the collecting system (26) the first (E) and third (H,G) components of the zoom system (25) are mounted on a common carriage (41) and are selectively positionable along the optical axis (21) whereas the second (F) and fourth (I) components of the zoom system (25) are fixedly positioned on the optical axis (21) whereby the zoom system (25) is optically-compensated and of variable effective focal length. The fourth (I) zoom system component is formed by a lens element having an aspheric refractive surface (17) but the refractive surfaces (9-16) of all other lens elements (E,F,GH) of the zoom system (25) are non-aspheric.

Abstract: An infrared radiation detecting system comprises an optical imaging system (25) for receiving radiation from a field of view (23) and delivering that radiation to an image surface (16). A background limited detector unit (26) having a detecting surface (.phi.) located in a cold shield housing having a cooled aperture (13) is spaced from image surface (16) and a transfer lens system (24) is interposed to transfer infrared radiation therebetween. Lens system (24) is arranged to focus the radiation at the detecting surface (.phi.) of the detector unit (26) such that the focussed radiation field curvature coincides with the physical curvature of detecting surface (.phi.), to form a pupil which is coincident in space with the position of the cooled aperture (13) and to dimension the pupil to match the dimension of the cooled aperture (13). To achieve these effects the transfer lens system (24) is formed by four lens elements (A,B,C,D) of selected power, axial spacing, and refractive surface curvature.

Abstract: An infrared objective lens system (15) comprises a primary lens group (13) air spaced from a secondary lens group (14) by means of a support assembly (16). The primary lens group (13) and secondary lens group (14) are aligned on a common optical axis (10) and are arranged to form a real image (9) at an external image surface from infrared radiation entering the system (15) through a pupil .0. in object space (11). Primary lens group (13) is self-compensated for chromatic aberrations, is positively powered and is made of material the refractive index of which is relatively temperature insensitive such as arsenic triselenide and/or zinc selenide. The secondary lens group (14) is positively powered, introduces minimal chromatic aberrations and is formed by a positively powered lens (C) and a negatively powered lens (D). Lens (C) is made of material the refractive index of which is relatively temperature insensitive such as arsenic triselenide.

Abstract: An afocal telescope (20) comprises an objective system (21) and an eyepiece system (23) aligned on a common optical axis (19), the objective system (21) forming a real image (24) of radiation received from object space (17) and eyepiece system (23) being arranged to provide a magnified view of the object space scene at a pupil .phi. in image space (18). The eyepiece system (23) is formed by a triplet of lens elements A,B,C of which A and B are positively powered and C is negatively powered. Element C has a concave refractive surface (6) adjacent image (24) and a convex refractive surface (5) which is separated from the adjoining refractive surface (4) of element B by an air space which, in the axial direction, is substantially zero on the axis (19) and which progressively increases in magnitude as the distance off axis increases.

Abstract: An afocal refractor telescope is formed by a fixed focus achromatic telephoto objective system (10) and a fixed focus eyepiece system (11) aligned on a common optical axis (12) and is arranged to provide an internal real image (13). The objective system (10) is formed by a primary lens element (D) and a secondary lens element (C) and the eyepiece system (11) has at least two lens elements (A, B). Each of the lens elements (A,B,C,D) of the telescope is made of a material having a useful spectral bandpass in the infrared wavelength region and has refractive surfaces (1,2,3,4,5,6,7,8) intercepting the optical axis (12), at least one of the refractive surfaces (7,8) of the primary objective lens element (D) being aspheric whereas the refractive surfaces (1,2,3,4,5,6) of the lens elements (A,B,C) are substantially spherical. The aspheric surface (7,8) possesses only a small degree of asphericity and is defined by an equation in which the third and higher order aspheric coefficients are zero.