Imaging apparatus and lens unit

A lens unit attachable to an imaging apparatus, comprising:

• a first lens terminal and a second lens terminal for communication with the imaging apparatus;
• and
• a lens control unit configured to perform switching between a first communication mode in which a clock signal is input via the first lens terminal and communication is performed with the imaging apparatus via the second lens terminal based on the clock signal and a second communication mode in which communication is performed with the imaging apparatus without inputting the clock signal,
• wherein the lens control unit determines a baud rate to be used in the second communication mode and transmits a first signal notifying completion of baud rate settings to the imaging apparatus.

A method of controlling an imaging apparatus to which a lens unit can be detachably mounted, that includes a first terminal and a second terminal for communication with the mounted lens unit, the method comprising:

• switching between a first communication mode in which a clock signal is output via the first terminal and communication is performed with the lens unit via the second terminal based on the clock signal and a second communication mode in which communication is performed with the lens unit without outputting the clock signal, and
• determining whether the lens unit is available for the second communication mode or not,
• wherein the first communication mode is continued if it is determined that the lens unit is not available for the second communication mode,
• wherein the second communication mode is performed at a baud rate determined by the lens unit if it is determined that the lens unit is available for the second communication mode, and
• wherein the second communication mode is set after a first signal notifying completion of baud rate settings is received from the lens unit.