Focus detecting apparatus for selecting the operating process in conformity with the contrast of an object

摘要

A focus detecting apparatus in which light distributions having their relative positional relation varying in conformity with the focus adjusted state of an objective optical system and based on an object are received by a light-receiving device having a plurality of picture elements and the output signal of the light-receiving device is operated in two different processes, and an evaluated values dependent on the contrast is operated in each of the processes and the evaluated values are compared with each other, and the result calculated in the process of better contrast is adopted as a value indicative of the focus adjusted state of the objective optical system.