Asahi Kogaku Kogyo Kabushiki Kaisha

Nobuhiko Matsudo

Osamu Sato

Isamu Hirai

Takayuki Sensui

Akio Takahashi

Masato Yamamoto

Toshimasa Yamanaka

Toshiyuki Kitazawa

Satoshi Nakano

Takenao Shishikura

Tadayuki Kirigaya

Hideaki Tsuji

A flashlight control apparatus having a device for emitting flashlight towards a subject and a device for receiving the light reflected from the subject through a photographing lens. An output is generated which corresponds to the received light which is time-integrated in order to calculate the amount of light received. An optimum integration level is calculated which is to be integrated. This optimum integration level corresponds to an optimum quantity of flashlight to be emitted by the emitting means, based on film speed information. A time limit is also calculated, which is shorter, by a predetermined length of time, than an optimum emission time of the emitting device. This optimum emission time is based on aperture value information and object distance information. The emitting device is controlled to stop emitting flashlight when the time limit elapses, in the case where a quantity of light received by the light receiving devices has reached an optimum quantity before the time limit elapses.

Flashlight control apparatus

A camera having a manually actuable switch for temporarily shifting the camera to an optimum exposure value so that exposure factors, based upon a manually set shutter speed and a manually set aperture value, are replaced by optimum exposure factors based upon a metered brightness of the object to be photographed when the camera is set to a non-program exposure mode. A clear button associated with the camera functions as a manually actuable switch for temporarily shifting an exposure mode of the camera to another exposure mode when the camera is set to a hyper-manual exposure mode. In the hyper-manual exposure mode, a photographer sets exposure factors by actuating a Tv electronic dial and an Av electronic dial. Actuation of the clear button when the camera is set to the hyper-manual exposure mode causes the set exposure factors to be replaced with optimum exposure factors that are automatically calculated in accordance with an object brightness Bv. Thus, operating the clear button (manually actuable switch for temporarily shifting to another exposure mode) results in the mode of the camera being changed from a mode in which exposure factors are manually set by a photographer (via the setting of a shutter speed and an aperture value) to a mode in which optimum exposure factors are set based upon a calculation performed by a processor of the camera.

Exposure control apparatus of camera

An exposure control apparatus of a camera, wherein a pair of exposure factors that include a shutter speed and a diaphragm value can be manually and independently set. Furthermore, in the exposure control apparatus, an exposure value determined in accordance with the exposure factors can be locked, and one of the exposure factors can be varied, based on the locked exposure value, when the other exposure factor is varied by the associated manual setting means.

An exposure control apparatus of a camera having a photometer, a film sensitivity detector, a calculator which calculates an exposure value, a diaphragm value and a shutter speed in accordance with a measurement by the photometer and the film sensitivity, an object distance detector, a strobe, a limit diaphragm value calculator that calculates a first limit diaphragm value, which varies with the film sensitivity, and a second limit diaphragm value, which varies with the object distance, when strobe light is emitted, and a minimum limit diaphragm value setting device which compares the first and second limit diaphragm values and selects the larger diaphragm value as the minimum limit diaphragm value to be used in the exposure control.

Exposure control apparatus of a camera

Growing community of inventors

Tokyo, Japan

Nobuhiko Matsudo