Accessory apparatus for communicating with an image pickup apparatus,image pickup apparatus for communicating with an accessory appparatus, and imaging system providing techniques for communicating between an accessory apparatus and an image pickup apparatus

An image pickup apparatus capable of communicating with an accessory apparatus by using a plurality of communication methods,

• the image pickup apparatus comprising:
• a mount for detachably attaching the accessory apparatus;
• and
• a camera-side controller configured to control communication with the accessory apparatus,
• wherein, when the accessory apparatus is attached to the image pickup apparatus, the camera-side controller performs initial communication for acquiring information about a communication method supported by the accessory apparatus, by using a first communication method, and
• wherein, in a state where a communication setting of the accessory apparatus is a setting corresponding to a second communication method different from the first communication method, the camera-side controller transmits to the accessory apparatus a signal for switching the communication setting of the accessory apparatus to a setting corresponding to the first communication method, and then transmits to the accessory apparatus a signal for switching a power state thereof from a first power state to a second power state which provides smaller power consumption than the first power state.

An accessory apparatus capable of communicating with an image pickup apparatus by using a plurality of communication methods, the accessory apparatus comprising:

• a mount for detachably attaching the accessory apparatus to the image pickup apparatus;
• and
• an accessory-side controller configured to:
• upon reception of a signal transmitted from the image pickup apparatus, switch between a first power state where communication with the image pickup apparatus is possible and a second power state which provides smaller power consumption than the first power state;
• and
• set a communication method to be used for communication with the image pickup apparatus that is performed at the time of switching from the second power state to the first power state.