Image-capturing apparatus, accessory apparatus and control method therefor

An accessory apparatus detachably attachable to an image-capturing apparatus, the accessory apparatus comprising:

• an accessory communicator configured to provide, with the image-capturing apparatus, a first data communication channel used for transmitting accessory data from the accessory apparatus to the image-capturing apparatus, and a second data communication channel used for transmitting camera data from the image-capturing apparatus to the accessory apparatus;
• and
• an accessory controller configured to perform communication with the image-capturing apparatus through the accessory communicator,
• wherein:
• the accessory controller is configured to be capable of switching its communication mode between a first communication mode and a second communication mode;
• and
• the accessory controller is configured to transmit the accessory data whose settings of parity bits are different in the first and second communication modes.

An image-capturing system including an image-capturing apparatus and an accessory apparatus detachably attachable to the image-capturing apparatus, the system comprising:

• a camera communicator included in the image-capturing apparatus and an accessory communicator included in the accessory apparatus, the camera and accessory communicators being configured to provide therebetween, a first data communication channel used for transmitting accessory data from the accessory apparatus to the image-capturing apparatus, and a second data communication channel used for transmitting camera data from the image-capturing apparatus to the accessory apparatus;
• and
• a camera controller included in the image-capturing apparatus and an accessory controller included in the accessory apparatus, the camera and accessory controllers being configured to perform communication therebetween through the camera and accessory communicators,
• wherein:
• the camera and accessory controllers are configured to be capable of switching their communication modes between a first communication mode and a second communication mode;
• and
• the camera controller is configured to cause the accessory controller to transmit the accessory data whose settings of parity bits are different between in the first and second communication modes.