Abstract: At a lens group position storage unit, the positions of a focus lens group and a zoom lens group detected at the time of a preset operation are stored. In response to an instruction for a go-home operation, a zoom lens group position comparison unit compares the current zoom lens group position with the position detected at the time of the preset operation. If the zoom lens group position assumed when the instruction for the go-home operation is issued is further toward the telephoto side relative to the zoom lens group position at the time of the preset operation, a defocus prevention unit issues a warning so as to prevent defocusing.

Abstract: At a lens group position storage unit, the positions of a focus lens group and a zoom lens group detected at the time of a preset operation are stored. In response to an instruction for a go-home operation, a zoom lens group position comparison unit compares the current zoom lens group position with the position detected at the time of the preset operation. If the zoom lens group position assumed when the instruction for the go-home operation is issued is further toward the telephoto side relative to the zoom lens group position at the time of the preset operation, a defocus prevention unit issues a warning so as to prevent defocusing.

Abstract: An autofocus system and photographic lens to convert a residual defocus amount which is corrected on the camera body side into an appropriate residual drive amount on the photographic lens side. The autofocus system includes, on the camera body side, a focus detection device to detect a defocus amount of a photographic lens, a lens movement information acquisition device to acquire lens movement information, a within-camera correction device to determine a residual defocus amount, correcting the lens movement after focus detection based on relational information representing a relationship between the defocus amount and the lens drive amount and movement information, and an information transmission device to transmit the residual defocus amount to the lens side.

Abstract: A lens barrel and a camera system are capable of precisely calculating a photographic magnification and a field range. The lens barrel having a focusing or zooming movable lens unit is stored with effective focal length data corresponding to a position of the movable lens unit, detects the position of the movable lens unit, outputs the corresponding effective focal length data and calculates the photographic magnification and the field range. An accuracy of a calculated value is thereby enhanced enough not to cause an underexposure on the whole or the underexposure in a peripheral portion as compared with a central portion.

Abstract: A camera system having a camera body adapted to operate with multiple types of interchangeable lenses, some of the lenses having an aperture ring and other of the lenses without an aperture ring. Based upon a signal, received via a contact point, a determination is made whether an attached interchangeable lens having an aperture ring is mounted on the camera body. Subsequently, if the attached interchangeable lens has an aperture ring, a control circuit permits aperture control of the lens photographic optical system by an aperture control circuit if an aperture interlocking ring of the camera body detects that the set aperture value is at a minimum value. The aperture control circuit restricts aperture control of the photographic optical system if the set aperture value is not at the minimum value.

Abstract: A position detecting device comprises a pattern member having conductive patterns arranged in plural tracks; a slidable member having plural sliding pieces capable of sliding on the conductive patterns, wherein each of the sliding pieces assumes either a conductive state in contact with one of the conductive patterns or a non-conductive state not in contact with the conductive pattern; a signal processing device for detecting sets of the conductive patterns and the sliding pieces in conductive state, by transmitting electrical signals through the conductive patterns and the sliding pieces; and a discriminating device for identifying the relative position between the conductive patterns and the sliding pieces when the the conductive patterns and the sliding pieces in conductive state are detected at least a predetermined number of times or over at least a predetermined period of time.

Abstract: An automatic focusing device for a camera capable of accommodating an interchangeable zoom lens which prevents inadvertently performing a moving subject tracking lens drive control when the zoom lens causes focus shift as a result of a zooming operation. The automatic focusing device operates in a first drive mode in which movement of the subject in the optical axis direction is detected and the moving subject is tracked by providing compensation for the drive amount of the lens according to the movement of the subject, and a second drive mode in which movement of the subject in the optical axis direction is not detected and compensation for the drive amount of the lens is not provided. A determination that the zoom lens causes focus shift during a zooming operation is made when the object distance is within a specified distance range, and a focus shift signal is output when focus shift will occur. An inhibition device inhibits the lens drive in the first lens drive mode in response to the focus shift signal.

Abstract: An automatic focusing device in which when a lens shifting range is arbitrarily limited and set with respect to the distance to a target object, the defocus amount and lens position are automatically detected, and the image plane shifting amount corresponding to the limited lens shifting range is calculated. Then, the corresponding image shifting amount and the detected defocus amount are compared. As a result of such comparison, if the defocus amount is found smaller, i.e., the target object is within the lens shift limiting range, the lens is shifted by the lens shifting amount thus calculated so as to perform focusing. If the defocus amount is found larger, i.e., the target object is outside the lens shift limiting range, the driving of the driving device is disabled so as not to shift the lens. If the defocus amount is found larger and the lens shifting is disabled, the defocus amount is again detected.

Abstract: A lens barrel mountable on a camera body includes a phototaking lens system, an absolute position detecting device for detecting the absolute position of the phototaking lens system in the axial direction, a phototaking distance data memory device for storing phototaking distance data corresponding to the absolute position of the phototaking lens system, an aberration data memory device for storing aberration data between a predetermined image plane and the actual image plane of the phototaking lens system, and a calculation device for correcting the phototaking distance data based on the aberration data, wherein the corrected phototaking distance data are transferred to the camera body.

Abstract: An automatic focusing camera system has a lens barrel with a focusing optical system, and a camera body. A focus detecting device in the camera body outputs a focus detecting signal. A calculating device in the camera body calculates driving information of the focusing optical system based upon the focus detecting signal. A driving device in the lens barrel has a driving power source and a transmission member for transmitting driving power to the focusing optical system to drive it based upon the driving information. First and second signal generators in the lens barrel, at respective final and initial stages of the transmission member, generate first and second driving signals in response to driving of the focusing optical system. A driving control device in the lens barrel controls position of the focusing optical system based upon the first driving signal and the driving information, and controls velocity of the driving power source based upon the second driving signal.

Abstract: An automatic focusing camera system has a lens barrel with a focusing optical system, and a camera body. A focus detecting device in the camera body outputs a focus detecting signal. A calculating device in the camera body calculates driving information of the focusing optical system based upon the focus detecting signal. A driving device in the lens barrel has a driving power source and a transmission member for transmitting driving power to the focusing optical system to drive it based upon the driving information. First and second signal generators in the lens barrel, at respective final and initial stages of the transmission member, generate first and second driving signals in response to driving of the focusing optical system. A driving control device in the lens barrel controls position of the focusing optical system based upon the first driving signal and the driving information, and controls velocity of the driving power source based upon the second driving signal.

Abstract: A photographing apparatus for electrically detecting manipulation of a manually manipulated member and driving a photographing lens into an in-focus state by driving a motor in accordance with the manipulation comprises a continuous drive device for driving the lens by driving the motor for a time corresponding to a manipulation time when the manual manipulation member is continuously manipulated longer than a predetermined time, and a fine drive device for driving the motor to drive the lens by a predetermined amount per manipulation which is independent from the manipulation time and variable in accordance with a photographing condition when the manual manipulation member is manipulated shorter than the predetermined time.

Abstract: A camera system is provided in which the entire performance is not deteriorated by corrective calculations for adapters, in information transmission between an interchangeable lens and an adapter. The adapter is equipped with an information processing device, capable of correcting at least a part of an information transmitted from the information processing device of the interchangeable lens, based on information specific to the adapter, and transmitting thus corrected information to the information processing device of the interchangeable lens.

Abstract: A printing apparatus for preparing a print image out of a subject image formed by a photographic optical system and recorded on a recording medium comprises a unit for supplying data on the optical performances of the photographic optical system, a unit for setting a trimming magnification determining the trim range of the subject image recorded on the recording medium, a unit for setting the size of the print image, a unit for setting a maximum enlarging magnification for enlarging the subject image to a print image on the basis of the data read and the trimming magnification; and a unit for determining a final enlarging magnification for enlarging the subject image to a print image on the basis of the maximum enlarging magnification and the size of the print image.

Abstract: An automatic focusing camera system has a lens barrel with a focusing optical system, and a camera body. A focus detecting device in the camera body outputs a focus detecting signal. A calculating device in the camera body calculates driving information of the focusing optical system based upon the focus detecting signal. A driving device in the lens barrel has a driving power source and a transmission member for transmitting driving power to the focusing optical system to drive it based upon the driving information. First and second signal generators in the lens barrel, at respective final and initial stages of the transmission member, generate first and second driving signals in response to driving of the focusing optical system A driving control device in the lens barrel controls position of the focusing optical system based upon the first driving signal and the driving information, and controls velocity of the driving power source based upon the second driving signal.

Abstract: A camera system in which by the mounting of a removably mountable lens, a plurality of electrical contacts between a camera body and the lens are brought into contact with one another and the transmission of information is effected between the camera body and the lens includes a camera body, a lens having no power source, a mechanical switch member provided in the lens, and power source actuating means for switching on the circuit power source of the camera body through the electrical contacts when the switch member is operated in a state in which the circuit power source is OFF.

Abstract: A camera which can be used for trimming shots and which has a lens whose optical performance can be read as optical-performance information comprises: a reader for reading the optical-performance information; an input device for inputting a trimming magnification; and a recorder for recording trimming information on a recording medium on the basis of the optical-performance information read and the trimming magnification that is set.

Abstract: An automatic focusing camera system has a lens barrel with a focusing optical system, and a camera body. A focus detecting device in the camera body outputs a focus detecting signal. A calculating device in the camera body calculates driving information of the focusing optical system based upon the focus detecting signal. A driving device in the lens barrel has a driving power source and a transmission member for transmitting driving power to the focusing optical system to drive it based upon the driving information. First and second signal generators in the lens barrel, at respective final and initial stages of the transmission member, generate first and second driving signals in response to driving of the focusing optical system. A driving control device in the lens barrel controls position of the focusing optical system based upon the first driving signal and the driving information, and controls velocity of the driving power source based upon the second driving signal.

Abstract: A camera system and a rear conversion lens both of which accurately calculate the distance .DELTA.X a focusing lens moves when the rear conversion lens is interposed between an interchangeable lens and the camera body, even when the distance .DELTA.Bf an image surface of the focusing lens shifts, increases, so that a subject can be focused quickly.A factor K.sub.0 for converting the distance the image surface of an interchangeable lens shifts and a factor C.sub.0 for correcting the conversion factor K.sub.0 are stored, and the magnification .beta.c and the focal length fc of the rear conversion lens are also stored independently of the above two factors. The distance .DELTA.X is calculated with precision. The subject can thus be automatically focused smoothly and quickly.

Abstract: A system camera provided with a rear conversion lens barrel interposed between an interchangeable photo-taking lens barrel and a camera body comprises a camera body having a focus detecting apparatus for detecting the amount of deviation of the image plane and a first converting device for correcting the amount of deviation of the image plane detected by the focus detecting apparatus, an interchangeable photo-taking lens barrel disposed forwardly of the camera body and having an interchangeable photo-taking lens and a first memory for storing therein data regarding the exit pupil position PO from the focal plane of the interchangeable photo-taking lens, a rear conversion lens barrel interposed between the interchangeable phototaking lens barrel and the camera body and having a rear conversion lens and a second memory for storing therein data regarding the magnification .beta..sub.R and focal length f.sub.