Abstract: An eyepiece lens has a single lens element having a positive optical power, and the single lens element has a refractive power of an aspherical surface and a diffractive power. The eyepiece lens satisfies the following condition:-0.0006<{1 /(fl.multidot..nu.)}+.phi.DOE/.nu.DOE<0.0002where fl represents the focal length resulting from both refractive effect and diffractive effect of the eyepiece lens, .nu. represents the Abbe number of the eyepiece lens, .phi.DOE represents the power resulting from the diffractive effect of the eyepiece lens, and .nu.DOE represents the Abbe-number-equivalent value resulting from the diffractive effect of the eyepiece lens.

Abstract: A subject image is formed on a focusing screen by a taking lens in a camera. The focusing screen is constituted by a liquid crystal whose light diffusion characteristic is variable. The light diffusion characteristic is varied according to an open aperture value of the taking lens which is attached to the camera.

Abstract: A finder has a finder field frame switching mechanism for switching and indicating two field frames relative to a reference field frame. The finder field frame switching mechanism performs switching of one field frame by a mechanical type switching mechanism, and switching of another field frame by liquid crystal. As a result, an inexpensive finder field frame switching mechanism of a simple structure can be provided.

Abstract: A system that is mounted in a camera capable of focal point detection and that performs correction of the focal point detection data in accordance with the temperature, wherein the temperature inside the photo-taking lens barrel is measured and the focal point detection data is corrected based on the temperature data for the interior of the photo-taking lens barrel. Using this construction, because the temperature of a lens element comprising the photo-taking lens can be accurately measured even where the ambient temperature of the camera has suddenly changed, for example, appropriate correction suitable for the temperature conditions may be performed. Also disclosed is a construction in which the correction of the focal point detection data is performed based on not only the temperature data but also the focal length data for the photo-taking lens.

Abstract: A camera includes a manually operable member having a plurality of distance measuring areas and for switching between exposure correction and AF area and between single photographing and continuous photographing. A viewfinder of the camera displays not only an object but also the above-described respective functions displayed on a LCD and switchable by the manually operable member. As a result, a photographer is allowed to perform photographing while looking at not only the object but also the state of the various functions displayed on the LCD in the finder.

Abstract: A zoom viewfinder system for a single reflex camera comprises a relay optical system through which said first object image is formed as a second object image and plural reflecting members for reflecting light rays of said first object image, wherein the reflecting members except one reflecting member provided closest to a first object image is moved in order to adjust an angle of light rays of the first object image to the reflecting members. The zoom viewfinder system also comprises a holder for holding the reflecting members located parallel in the relay optical system in order to determine relative positions of the reflecting members precisely. The zoom viewfinder system further comprises holding members for holding plural parts of an optical system respectively, wherein each part is fixed to compose a viewfinder system, so that assembly and maintenance can be easy and the optical axis can be prevented from deviating.

Abstract: A camera has an electronic viewfinder for displaying an image of a subject to be photographed in accordance with image data from a scene. The displayed image encompasses an area larger than that of the scene to be photographed, to enable the camera user to view objects and events outside of the photographic frame. In addition, the image data can be processed in accordance with differing photographic conditions, such as changes in shutter speed, aperture or electronic flash emission, to permit the user to view the changes that occur under the differing conditions.

Abstract: A flash apparatus which allows flashlight photographing of various subjects in a photographing screen in appropriate exposure by simple operation without failure. The flash apparatus comprises a flashlight emitting section having a predetermined irradiation angle with respect to a light emission optical axis, and irradiating direction changing means for automatically changing the direction of the light emission optical axis of the flashlight emitting section in response to subject information such as distribution information of brightness values of or distances to subjects in a photographing screen. Also a camera is disclosed which assures photographing of a main subject with appropriate exposure even when the main subject is in a backlighted condition or when another body is positioned nearer to the camera than the main subject.

Abstract: A finder display apparatus provides a display of information associated with the photographing within a finder field. The finder display apparatus has a reflecting surface, a polarizing plate and an electro-optical display device constituted by a twisted nematic liquid crystal arranged between the reflecting surface and the polarizing plate. The reflecting plate is provided to a Porro prism and has a polarization characteristic different by 90.degree. from the polarization characteristic of the polarizing plate.

Abstract: In a remote controllable camera system having a remote controller, a camera body provides with calculation means for calculating an angle between the remote controller and an optical axis of a photo-taking lens and moving means for moving the optical axis to a point where the angle is a predetermined value. Furthermore, the camera body provides with judging means for judging whether or not the remote controller is within the field of view of the photo-taking lens and displaying means for displaying the judging result of the judging means.

Abstract: A finder optical system is shown which includes a photo-taking lens, a mirror reflecting light rays passed through the photo-taking lens upward, a focusing screen on which a first object image is formed, a relay lens system through which the first object image is reformed as a second object image smaller than the first object image, and an eye piece which enlarges second object image. The relay lens system is located above the focusing screen and parallel to an optical axis of the photo-taking lens. The finder optical system allows for compactness in both depth and height.

Abstract: A camera having a blurring correction apparatus according to the present invention includes a photographic lens for forming an image of an object to be photographed, a detecting apparatus for detecting the degree of movement of the formed image of the object, a correcting apparatus operative at least during exposure time for correcting the position of the image of the object in response to a detection output of the detecting apparatus so as to compensate the movement of the image of the object, a setting apparatus for setting exposure time, a calculating apparatus for calculating the amount of movement of the image of the object produced during exposure time based on the detection output of the detecting apparatus and the set exposure time, and a prohibiting apparatus for prohibiting the operation of the correcting apparatus when the amount of movement of the image of the object produced during exposure time is smaller than a predetermined value.

Abstract: A diffusion degree of a focusing screen is changed by applying voltage to the focusing screen since the focusing screen comprises liquid crystal material whose molecules are penetrated onto a polymer network. The diffusion degree is changed according to the selected exposure mode. Brightness of an object, measured through the focusing screen, is corrected on the basis of applied voltage, an open aperture value and an exit pupil length of a photo-taking lens. Furthermore, the applied voltage, namely, the diffusion degree is changed according to the object brightness.

Abstract: An exposure control device for a camera comprising; first means for measuring light from a central area of an object field, said first measuring means including a plurality of means for receiving light from different portions within the central area, respectively; second means for measuring light from a surrounding area other than the central area, the surrounding area being greater than each portion within the central area; means for selecting between a first exposure control mode and a second exposure control mode; and means for controlling exposure in accordance with one of said plurality of receiving means in said first exposure control mode, and in accordance with all of said plurality of receiving means and said second measuring means in said second exposure control mode.

Abstract: A camera is capable of switching normal photographing mode and panoramic photographing mode to each other and has a view finder for checking a photographing range. The view finder includes a visual frame display device, a device for varying magnification of the view finder, a control device. The visual frame display device switches a visual frame for displaying the normal photographing mode and a visual frame for displaying the panoramic photographing mode. The control device switches the visual frame display device from the visual frame for displaying the normal photographing mode to the visual frame for displaying the panoramic photographing mode and allows the magnification varying device to increase the magnification of the view finder.

Abstract: The disclosure relates to the camera system comprises a photo-taking lens including a lens unit movable in direction other than parallel to an optcical axis of the photo-taking lens and a driver unit for driving the movable lens unit in the direction other thatn parallel to the optical axis of the photo-taking lens during a exposure operation. Therefore the camera system is capable of taking photography with special effect.

Abstract: A camera having a blurring correction apparatus according to the present invention includes a photographic lens for forming an image of an object to be photographed, a detecting apparatus for detecting the degree of movement of the formed image of the object, a correcting apparatus operative at least during exposure time for correcting the position of the image of the object in response to a detection output of the detecting apparatus so as to compensate the movement of the image of the object, a setting apparatus for setting exposure time, a calculating apparatus for calculating the amount of movement of the image of the object produced during exposure time based on the detection output of the detecting apparatus and the set exposure time, and a prohibiting apparatus for prohibiting the operation of the correcting apparatus when the amount of movement of the image of the object produced during exposure time is smaller than a predetermined value.

Abstract: A camera which has a photo-taking lens capable of zooming, and a viewfinder which shows a first photographing range and a display which displays one frame defining a second photographing range smaller than the first photographing range, wherein out of photographing range showing mode is provided. And when the out of photographing range mode is selected, after zooming operation is carried out, the second photographing range is exposed on a film, whereby the visual field in the finder can be enlarged and, provided that a camera has a focus detector, the focus detecting area can be relatively enlarged.

Abstract: In a finder optical system provided separately from a taking lens system, an objective lens system forms a primary image which is an inverted image of a subject, a relay lens system erects the primary image formed by the objective lens system to form a secondary image which is an erecting image and can change the size of the secondary image, and an ocular enlarges the secondary image formed by the relay lens system and can change the enlargement ratio.The finder optical system is useful for a camera constituting the trimming system.

Abstract: A finder optical system provided separately from a photo-taking lens comprises, from the object side: an object lens from forming a primary image which is an inverted image of an object and for erecting the primary image to form an erecting image; and an eyepiece for enlarging said erecting image. The object lens comprises a gradient index lens.