Device for determining whether focus detection may be accurately performed using characteristic data of an interchangeable lens and focus detection device

A device for deciding whether focus detection may be accurately performed in a camera, comprising:

• an interchangeable lens including at least one circular aperture;
• a plurality of focus detection devices located in the camera which perform focus detection for respective focus detection regions within a photographic image plane, and which output respective focal point positions;
• a lens memory which stores data representing an exit beam for an optional image height;
• a camera memory located in the camera which stores data representing characteristics of the plurality of focus detection devices;
• a decision unit, coupled to the lens memory and to the camera memory, to determine whether focus detection may be accurately performed for each respective focus detection device based upon the data stored in the lens memory and based upon the data stored in the camera memory.

An apparatus for determining whether focus detection may be accurately performed in a camera, comprising:

• an interchangeable lens including at least one circular aperture;
• a lens memory to store data representing an exit beam for an optional image height, the data representing the exit beam including a position and size of the at least one circular aperture;
• a camera memory to store data representing characteristics of a focus detection device;
• and
• a decision unit, coupled to the lens memory and the camera memory, to determine whether focus detection may be accurately performed based upon the data stored in the lens memory and the data stored in the camera memory.

A device for determining whether focus detection may be accurately performed in a camera, comprising:

• an interchangeable lens mounted on the camera which includes at least one circular aperture;
• a focus detection device located in the camera to perform focus detection for a focus detection region and to output a focal point position, the focus detection device including a rangefinder optical device;
• a lens memory to store data representing an exit beam for an optional image height, the data stored in the lens memory including data representing a position and a size of the at least one circular aperture;
• a camera memory to store data representing characteristics of the focus detection device, the characteristic data stored in the camera memory including data representing the position and shape of an entrance pupil of the rangefinder optical device;
• and
• a decision unit, coupled to the lens memory and to the camera memory, to determine whether focus detection may be accurately performed based upon the data stored in the lens memory and based upon the characteristic data stored in the camera memory.

A device for deciding whether focus detection may be accurately performed in a camera, comprising:

• an interchangeable lens including at least one circular aperture;
• a plurality of focus detection devices located in the camera which perform focus detection for respective focus detection regions within a photographic image plane, and which output respective focal point positions;
• a lens memory to store data representing an exit beam for an optional image height, the data representing the exit beam for an optional image height including a position and a size of the at least one circular aperture;
• a camera memory located in the camera which stores data representing characteristics of the plurality of focus detection devices;
• and
• a decision unit, coupled to the lens memory and to the camera memory, to determine whether focus detection may be accurately performed for each respective focus detection device based upon the data stored in the lens memory and based upon the data stored in the camera memory.