To provide a lens barrel capable of excellently adjusting a focus, a camera body, and a camera system.
A lens barrel 200 includes: a lens mount 201 to which a camera body 100 can be attached; a diaphragm 211 for adjusting the quantity of light passing through an image formation optical system 210; a diaphragm drive part 212 for driving the diaphragm 211 to change the diaphragm diameter of the diaphragm 211; a lens side transmitting and receiving part 217 capable of transmitting and receiving a signal to and from the camera body 100; and a lens control part 203 for controlling the lens side transmitting and receiving part 217 so as to transmit a diaphragm signal corresponding to a third diaphragm diameter larger than a first diaphragm diameter and a second diaphragm diameter, when the diaphragm diameter of the diaphragm 211 is changed from the first diaphragm diameter to the second diaphragm diameter.
TAKAHARA HIROAKI
TOMITA HIROYUKI
Takao Watanabe