Abstract: A program rewritable camera includes camera elements for conducting camera operation, a control circuit for controlling said camera elements in response to coded control orders, a first memory for storing said control orders and an input circuit for enabling part or all of the contents stored in said first memory to rewrite by a peripheral device disposed outside the camera body. Connecting the peripheral device to the camera, camera functions desired by a photographer can be transferred to and stored in said first memory from the peripheral device in which various camera functions have been stored, through said input circuit to put the camera into action.

Abstract: An automatic focusing camera, after determining composition of an object being photographed within a range finding frame disposed at the center of a finder, repeats operations of detecting a range difference between an image forming position and a predetermined focusing position of the object and of storing the detected range difference, before a shutter release button is half-depressed, and, after being half-depressed, drives a taking lens in accordance with a range difference based on the latest information stored immediately before the half-depression to stop the taking lens at the predetermined focusing position, thereby enabling the lens setting without a time lag even when the object being photographed is in a low brightness.

Abstract: Apparatus for delivering distance information of a camera includes counter means which counts a relative distance corresponding to a movement of a taking lens. The counter means is reset when the taking lens reaches a reference position located at infinity. Using stored data (absolute distance factors) which is specific to a taking lens and the count in the counter means, an absolute distance is derived.

Abstract: A process for preparing a fluorine-containing polymer having carboxyl groups, which comprises subjecting a fluorine-containing polymer having sulfonyl halide groups bonded to it to an oxidation reaction at a temperature of not more than 250.degree. C.; and a process for electrolysis, using as a diaphragm a member of the polymer obtained by the above process.

Abstract: A process for preparing a fluorine-containing polymer having carboxyl groups, which comprises subjecting a fluorine-containing polymer having sulfonyl halide groups bonded to it to an oxidation reaction at a temperature of not more than 250.degree. C.; and a process for electrolysis, using as a diaphragm a member of the polymer obtained by the above process.