| 摘要 |
PURPOSE:To speed up processing by representing data on a aperture value and data on a focal length as numerals which vary logarithmically, and setting numerals which increase when the aperture and focal length become double so that they increase by the same value. CONSTITUTION:Hexadecimal data corresponding to the focal length of a lens 2 is stored in the data area in the MCU20 of the lens. The decimal data of this signal which is represented as (x) varies logarithmically with the focal length so that (x) increase by 24, 48... as the focal length becomes twice, four times... and decrease by 24 when the focal length becomes a half. Similarly, hexadecimal data corresponding to teleconversion power is stored in the MCU30 of an intermediate accessory 3 and the decimal data (x) varies logarithmically with the teleconversion power. The microcomputer MCU10 of a camera body 1 performs specific arithmetic based upon an AF controlled variable and an AF conversion coefficient stored in the lens 2 and accessory 3 to determine a controlled variable when the accessory is combined with the lens, thereby performing specific automatic focus control.
|
