Abstract: A view finder device has a Poro prism and a first optical system facing an emergent plane of the Poro prism. The first optical system is positioned beside the Poro prism and opposite to a recording medium passage through which an electro-developing recording medium is moved. A relay optical system is provided behind the recording medium passage, so that the eye point of the view finder is separated from the first optical system. A second optical system is provided behind the relay optical system, so that the image formed by the relay optical system is observed. Since the electro-developing recording medium can be moved between the first optical system and the relay optical system, the finder optical system can be disposed at a lower position.

Abstract: Disclosed is a dual image coincidence type finder system for a camera. Within a finder field, a dual image composed of superimposed two images is formed. A light deflecting system is provided to change degree of relative displacement between the superimposed two images. The light deflecting system is controlled to change the degree of relative displacement between the superimposed two images in accordance with an object distance.

Abstract: An eyepiece optical system, which is used in a single lens reflex camera having a penta mirror, includes a negative first single lens element, a positive second single lens element, and a negative third single lens element, in this order from the penta mirror; wherein the second single lens element is a diopter adjusting lens element which is adjustable along the optical axis; and the following conditions are satisfied: −2<f1/fe<0  (1) 0.2<f2/fe<0.5  (2) −10<f3/fe<−1  (3) wherein f1 designates the focal length of the first single lens elements; f2 designates the focal length of the second single lens element; f3 designates the focal length of the third single lens element; and fe designates the focal length of the entire eyepiece optical system when the diopter is −1.0.

Abstract: An eyepiece optical system, which is used in a single lens reflex camera having a penta mirror, includes a negative first lens group, a positive second lens group, and a negative third lens group, in this order from the penta mirror; wherein the second lens group is a diopter adjustment lens group which is adjustable along the optical axis direction; and the following conditions are satisfied: −0.8<f1G/fe<−0.2  (1) 0.2<f2G/fe<0.5  (2) −15<f3G/fe<−1  (3) wherein f1G designates the focal length of the first lens group; f2G designates the focal length of the second lens group; f3G designates the focal length of the third lens group; and fe designates the focal length of the entire eyepiece optical system when the diopter is −1.0.

Abstract: A lens having color correction data includes a memory in which the color correction data necessary to make the color of an image of an object to be recorded, formed by the lens, coincident with the color of the object perceived through the naked eye is stored.

Abstract: A zooming optical system is provided with a plurality of lens groups that are moved to change a focal length of the zooming optical system. One of the plurality of lens groups including an aperture member has constituted to have (I) a focusing lens group that is driven to move for focusing, and (II) a image-vibration compensation lens group that is driven to move for compensating trembling of image due to a hand-vibration applied to the zooming optical system. The aperture member does not move when the focusing lens group or the image-vibration compensation lens group is driven to move.

Abstract: In a SLR camera having a diopter adjusting lens element movable along the optical axis, the movement of which causes a change in the apparent visual angle, there is provided a finder optical system including a field frame size varying mechanism for varying the size of the opening of the field frame, and an association mechanism for driving the field frame size varying mechanism so that the change in the apparent visual angle of the finder optical system is compensated when the diopter is varied by moving the diopter adjusting lens element.

Abstract: A view finder device has a Poro prism and a first optical system facing an emergent plane of the Poro prism. The first optical system is positioned beside the Poro prism and opposite to a recording medium passage through which an electro-developing recording medium is moved. A relay optical system is provided behind the recording medium passage, so that the eye point of the view finder is separated from the first optical system. A second optical system is provided behind the relay optical system, so that the image formed by the relay optical system is observed. Since the electro-developing recording medium can be moved between the first optical system and the relay optical system, the finder optical system can be disposed at a lower position.

Abstract: Disclosed is a real image type finder optical system which is provided with an objective optical system having a positive power, an erecting optical system for erecting a reversed real image formed by the objective optical system, an eyepiece optical system for observing the real image formed by the objective optical system and erected by the erecting optical system, an information display element provided in the objective optical system, the information display element displaying information to be observed in a field of view of the finder optical system, and a partial mirror surface provided on an object side with respect to the information display element, the partial mirror allowing a part of light from the object to pass therethrough and reflecting light from the information display element towards the eyepiece optical system.

Abstract: A real-image finder optical system includes a positive objective optical system, an image-erecting optical system and an eyepiece optical system, in this order from the object. The image-erecting optical system includes a pattern display surface having a reflective pattern, and a half mirror surface, transmitting a portion of the light rays incident from the object, and again reflecting the light rays having been reflected from the pattern display surface. The real-image finder optical system forms a real image of the object formed through the objective optical system and a virtual image of a pattern on the pattern display surface formed by an optical system including the half mirror surface so that an operator can simultaneously view both the real image of the object and the virtual image of the pattern through the eyepiece optical system; and the real-image finder optical system satisfies the condition:0<d.sub.1 /f.sub.e .ltoreq.0.1 (1)wherein d.sub.

Abstract: A real image type finder optical system is provided with an objective optical system having a positive power, an erecting optical system for erecting a real image formed by the objective optical system and an eyepiece optical system for observing the real image formed by the objective optical system and erected by the erecting optical system. An information display surface provided in the eyepiece optical system, the information display surface displaying information to be observed in a field of view of the finder optical system. A partial mirror surface is provided within the eyepiece optical system, on an object side with respect to the information display surface. The partial mirror surface allows a part of light incident from the object to pass therethrough, and reflects light incident from the information display surface towards the eye side.

Abstract: A viewfinder optical system for a real-image type viewfinder has a positive objective lens system for obtaining a finder-image, and an erecting optical system for converting the finder-image into an erected image. The erecting system includes a mirror for deflecting an optical axis of the objective lenses, and at least a part of the mirror is formed as a light-transmitting area. The viewfinder optical system further comprises an ocular lens for viewing the finder-image, and an optical system for optically producing an information pattern, such as a viewing-field-frame, to be superimposed on the finder-image. The projecting system includes a projecting lens which focuses and forms the frame-pattern on an image-forming plane, defined by the objective lens system, through the light-transmitting area of the mirror, so that the frame-pattern is superimposed on the finder-image.

Abstract: A real-image finder optical system is provided with an information display element located between an image plane of an objective optical system and a moving lens group of the objective optical system, and a partial mirror surface provided on an object side with respect to the information display element. The finder optical system includes the objective optical system having a positive power, an erecting optical system for erecting a reversed real image formed by the objective optical system, and an eyepiece optical system for observing the real image. Magnification of the finder optical system varies with the movement of at least one moving lens group of the objective lens system in a direction of an optical axis.

Abstract: Disclosed is a finder system for a camera. The finder system has real-image type first and second optical systems apart by a predetermined base length. Light passed through the first and second objective optical systems are combined and superimposed images are formed which is defined within a finder field. The second objective optical system is provided with a rotatable mirror which varies a direction of an optical axis of the second objective optical system with respect to the optical axis of the first objective optical system to vary degree of coincidence of the superimposed images. A rotation angle of the rotatable mirror is controlled based on information related to an object distance and a position within the finder field.

Abstract: A real-image finder comprises an objective optical system which forms an image of an object to be viewed; a field frame member located on a primary image forming plane on which the image formed by the objective optical system is formed; an ocular optical system through which the object image formed on the primary image forming plane; and an image erecting optical system which erects the object image formed by the objective optical system. The transparent members are provided on the front and rear surfaces of the field frame, and the thickness of the transparent members are determined so that if a foreign matter sticks to the end surfaces of the transparent members that are opposite to and located away from the field frame member, no foreign matter can be viewed through the ocular optical system.

Abstract: A zoom lens system comprising at least three lens groups including a positive first lens group, a positive second lens group having at least one negative lens element, and a third lens group having a negative focal length, wherein upon zooming from the shortest focal length toward the longest focal length, all the lens groups are moved toward the object side, and the distance between the first and second lens groups increases and the distance between the second and third lens groups decreases, and wherein the system satisfies the conditions (1) -0.3<f.sub.W /f.sub.1G +f.sub.W /f.sub.2G +f.sub.W /f.sub.3G <0, and (2) 1.845<N.sub.2Gn, wherein f.sub.W designates the focal length of the entire optical system at the short focal length extremity, f.sub.1G designates the focal length of the first lens group (f.sub.1G >0), f.sub.2G designates the focal length of the second lens group (f.sub.2G >0), f.sub.3G designates the focal length of the third lens group (f.sub.3G <0), N.sub.

Abstract: A camera having a real-image finder includes a photographing lens system, a real image type view finder separate from the photographing lens system, a focusing plate having a split image prism placed in the vicinity of an image forming position in which an object image is formed by the real image type view finder, an object distance data detection means, a photographing lens driving motor for moving the photographing lens system to focus the same, a finder driving motor for driving the finder to focus the same, and a controller for controlling the photographing lens driving motor and the finder driving motor in accordance with the object distance data so as to focus the photographing lens system and the finder on an aiming object. The invention is also directed to a control method of a camera having the same.

Abstract: A viewfinder of a camera having a multi-point type auto-focus function, in which a photographing lens can be focused on one of a plurality of objects in a plurality of focus detection zones within the field of view, when viewed through a viewfinder, includes a focusing plate which is provided with a plurality of split-image prisms corresponding to the focus detection zones within the finder field of view.

Abstract: Disclosed is a range finder system which includes a virtual image type first optical system for observing an object, and a second optical system for electronically capturing image of at least a part of the object. The range finder system is provided with an LCD (liquid crystal display) which displays the image captured by the second optical system. The image displayed on the liquid crystal display is directed to the virtual image type finder optical system, and the image as displayed on the LCD is combined with the image observed through the first optical system. Thus, two images are observed by a photographer as superimposed. A display controller controls the LCD so that the degree of coincidence of the superimposed images is varied in the direction of a base length based on an object distance information.

Abstract: A zoom lens system for a compact camera, having a zoom ratio of approximately 2 or 3 and a smaller overall lens length at the telephoto end than the focal distance at the telephoto end, and which optically experiences only a small focus shift due to environmental changes such as temperature or humidity. The zoom lens system includes a positive lens group and a negative lens group. A positive plastic lens element is disposed in either the positive lens group or the negative lens group. The magnification of the system is adjusted by varying .?.the.!. .Iadd.a .Iaddend.distance between the positive and negative lens groups. The zoom lens system satisfies the following conditions:0.9<f.sub.t /f.sub.p <1.6 (1)0.6<m.sub.p '-m.sub.p <1.2 (2).?.2.9<.!. .Iadd.3.13.ltoreq..Iaddend.m.sub.MAX <4.0 (3)where f.sub.t is the focal length of the overall system at the telephoto end, f.sub.p is the focal length of the positive plastic lens element, m.sub.