Abstract: A camera body at which one or more camera accessories, at which light from a subject enters, are detachably mountable, includes: a body-side terminal; and a communication unit that communicates with at least one of the camera accessories, wherein: the communication unit requests, via the body-side terminal, the camera accessory for a discriminating signal indicating whether or not another camera accessory capable of communicating with the camera body is mountable on a subject side of the camera accessory.

Abstract: A camera body at which one or more camera accessories, at which light from a subject enters, are detachably mountable, includes: a body-side terminal; and a communication unit that communicates with at least one of the camera accessories, wherein: the communication unit requests, via the body-side terminal, the camera accessory for a discriminating signal indicating whether or not another camera accessory capable of communicating with the camera body is mountable on a subject side of the camera accessory.

Abstract: A camera body, to which an accessory is mountable, includes a first communicator that transmits a first clock signal to the accessory to communicate with the accessory in synchronization with the first clock signal, and a second communicator that receives a second clock signal output from the accessory to communicate with the accessory in synchronization with the second clock signal. A value specifying a communication specification of the second communicator is transmitted between the first communicator and the accessory.

Abstract: An accessory that is mountable at a camera body and is capable of communicating with the camera body, includes: a first transmission unit capable of transmitting information pertaining to a drive target member that is driven by a drive unit to the camera body according to at least one communication specification; and a second transmission unit that transmits to the camera body a first value specifying a communication specification according to which the information is transmitted to the camera body, wherein: the first transmission unit transmits the information pertaining to the drive target member to the camera body according to the communication specification specified by the first value.

Abstract: An accessory that is mountable at a camera body and is capable of communicating with the camera body, includes: a transmission unit capable of transmitting information pertaining to a drive target member that is driven by a drive unit to the camera body according to at least one communication specification; and a reception unit that receives from the camera body a first value specifying a communication specification according to which the information is transmitted to the camera body, wherein: the transmission unit transmits the information pertaining to the drive target member to the camera body according to the communication specification specified by the first value.

Abstract: An accessory that is mountable at a camera body and is capable of communicating with the camera body, includes: a first transmission unit capable of transmitting information pertaining to a drive target member that is driven by a drive unit to the camera body according to at least one communication specification; and a second transmission unit that transmits to the camera body a first value specifying a communication specification according to which the information is transmitted to the camera body, wherein: the first transmission unit transmits the information pertaining to the drive target member to the camera body according to the communication specification specified by the first value.

Abstract: An interchangeable lens that is removably attachable to a camera body, includes: a first clock receiving unit that receives a first clock from the camera body; a second clock transmitting unit that transmits a second clock to the camera body; a lens that drives by receiving a driving force from a first driving member; a diaphragm member that drives by receiving a driving force from a second driving member; a receiving unit that receives an instruction from the camera body synchronized with the first clock; a first transmitting unit that periodically transmits positional information on the lens in synchronization with the second clock, to the camera body; and a second transmitting unit that transmits a state of the diaphragm member based on the instruction in synchronization with the first clock, to the camera body.

Abstract: An interchangeable lens that is removably attachable to a camera body includes: a moving member that is movable within the interchangeable lens; a first communication unit that performs first communication with the camera body; and a second communication unit that performs second communication in which data is periodically transmitted to the camera body; wherein: the data transmitted in the second communication includes first information indicating a position of the moving member and second information that can be used for calculation of a movement amount of the moving member.

Abstract: A camera body at which one or more camera accessories, at which light from a subject enters, are detachably mountable, includes: a body-side terminal; and a communication unit that communicates with at least one of the camera accessories, wherein: the communication unit requests, via the body-side terminal, the camera accessory for a discriminating signal indicating whether or not another camera accessory capable of communicating with the camera body is mountable on a subject side of the camera accessory.

Abstract: An accessory that is mountable at a camera body and is capable of carrying out communication with the camera body, includes: a creation unit that creates first information pertaining to a position of a drive target member in the accessory; an accessory-side reception unit that receives second information pertaining to the communication from the camera body; a calculation unit that calculates third information related to a time period between reception of the second information and creation of the first information by the creation unit; and an accessory-side first transmission unit that transmits the third information to the camera body.

Abstract: A camera body at which one or more camera accessories, at which light from a subject enters, are detachably mountable, includes: a body-side terminal; and a communication unit that communicates with at least one of the camera accessories, wherein: the communication unit requests, via the body-side terminal, the camera accessory for a discriminating signal indicating whether or not another camera accessory capable of communicating with the camera body is mountable on a subject side of the camera accessory.

Abstract: An accessory includes: a clock transmission unit that transmits a first clock signal; a first transmission unit that transmits to the camera body information pertaining to a drive target member in synchronization with the first clock signal; a clock reception unit that receives a second clock signal from the camera body; a second transmission unit that transmits to the camera body a first value indicating a communication specification according to which the first transmission unit transmits the information to the camera body in synchronization with the second clock signal; a reception unit that receives from the camera body a second value in synchronization with the second clock signal, indicating a communication specification; and a control unit that engages the first transmission unit to start transmitting the information according to the communication specification indicated by the second value, upon receiving the second value after the first value has been transmitted.

Abstract: A camera accessory, at which light from a subject enters, detachably mountable at a camera body, includes: a communication unit that communicates with the camera body; and a first storage unit that stores a discriminating signal indicating whether or not another device capable of communicating with the camera body is mountable on a subject side of the camera accessory, wherein: the communication unit transmits the discriminating signal to the camera body.

Abstract: An interchangeable lens that is removably attachable to a camera body, includes: a first clock receiving unit that receives a first clock from the camera body; a second clock transmitting unit that transmits a second clock to the camera body; a lens that drives by receiving a driving force from a first driving member; a diaphragm member that drives by receiving a driving force from a second driving member; a receiving unit that receives an instruction from the camera body synchronized with the first clock; a first transmitting unit that periodically transmits positional information on the lens in synchronization with the second clock, to the camera body; and a second transmitting unit that transmits a state of the diaphragm member based on the instruction in synchronization with the first clock, to the camera body.

Abstract: An accessory that is mountable at a camera body and is capable of communicating with the camera body, includes: a transmission unit capable of transmitting information pertaining to a drive target member that is driven by a drive unit to the camera body according to at least one communication specification; and a reception unit that receives from the camera body a first value specifying a communication specification according to which the information is transmitted to the camera body, wherein: the transmission unit transmits the information pertaining to the drive target member to the camera body according to the communication specification specified by the first value.

Abstract: An accessory that is mountable at a camera body and is capable of carrying out communication with the camera body, includes: a creation unit that creates first information pertaining to a position of a drive target member in the accessory; an accessory-side reception unit that receives second information pertaining to the communication from the camera body; a calculation unit that calculates third information related to a time period between reception of the second information and creation of the first information by the creation unit; and an accessory-side first transmission unit that transmits the third information to the camera body.

Abstract: An interchangeable lens that is removably attachable to a camera body includes: a moving member that is movable within the interchangeable lens; a first communication unit that performs first communication with the camera body; and a second communication unit that performs second communication in which data is periodically transmitted to the camera body; wherein: the data transmitted in the second communication includes first information indicating a position of the moving member and second information that can be used for calculation of a movement amount of the moving member.

Abstract: An accessory that is mountable at a camera body and is capable of communicating with the camera body, includes: a first transmission unit capable of transmitting information pertaining to a drive target member that is driven by a drive unit to the camera body according to at least one communication specification; and a second transmission unit that transmits to the camera body a first value specifying a communication specification according to which the information is transmitted to the camera body, wherein: the first transmission unit transmits the information pertaining to the drive target member to the camera body according to the communication specification specified by the first value.

Abstract: A camera accessory, at which light from a subject enters, detachably mountable at a camera body, includes: a communication unit that communicates with the camera body; and a first storage unit that stores a discriminating signal indicating whether or not another device capable of communicating with the camera body is mountable on a subject side of the camera accessory, wherein: the communication unit transmits the discriminating signal to the camera body.

Abstract: An accessory includes: a clock transmission unit that transmits a first clock signal; a first transmission unit that transmits to the camera body information pertaining to a drive target member in synchronization with the first clock signal; a clock reception unit that receives a second clock signal from the camera body; a second transmission unit that transmits to the camera body a first value indicating a communication specification according to which the first transmission unit transmits the information to the camera body in synchronization with the second clock signal; a reception unit that receives from the camera body a second value in synchronization with the second clock signal, indicating a communication specification; and a control unit that engages the first transmission unit to start transmitting the information according to the communication specification indicated by the second value, upon receiving the second value after the first value has been transmitted.