Display control processing for the difference in the degree of focus between the left and right images, executed by the system control unit 218, will be described next with reference to the flowchart in FIG. 14. This processing is executed when the binocular lens unit 300 is mounted to the camera 100. Additionally this processing is realized by the system control unit 218 loading a program recorded in the non-volatile memory 220 into the system memory 219 and executing the program. The display control processing for the difference in the degree of focus between the left and right images is executed in parallel with the live view display processing. The processing can also be executed in parallel with the focus guide display control processing described in the second embodiment.
In step S1001, the system control unit 218 obtains the defocus amount, and the reliability thereof, for the right eye optical system 301R and the left eye optical system 301L from the image processing unit 214. If the focus guide display control processing is being executed, the defocus amount and reliability obtained in step S602 of FIG. 11 may be referenced. The system control unit 218 then determines whether the reliability of at least one of the defocus amounts is low. If the system control unit 218 determines that the reliability of at least one of the defocus amounts is low, step S1008 is executed, and if not, step S1002 is executed.
