Imaging apparatus and accessory

An accessory, comprising:

• a second mount configured to bayonet couple with a first mount on an imaging apparatus,
• wherein the second mount has a plurality of contact faces disposed following the circumferential direction of the second mount and configured for electrical connection to a plurality of contact pins provided on the first mount in a case that the second mount is bayonet-coupled to the first mount, the number of the plurality of contact faces being an even number that is four or larger,
• wherein, in a normal position of the imaging apparatus in a state of being bayonet-coupled to the accessory, when viewing the imaging apparatus from the first mount side to which the second mount is coupled, a line extending from an center axis of the first mount in the gravitational direction and an opposite direction from the gravitational direction is taken as a first mount center line, and a line orthogonal to the center axis and the first mount center line is taken as a second mount center line,
• wherein the plurality of contact faces include a pair of contact faces adjacent to each other and having a first distance therebetween, and a pair of contact faces adjacent to each other and having a second distance different from the first distance therebetween,
• wherein the plurality of contact faces include a first contact face that overlaps the first mount center line, in a state where the second mount is coupled to the first mount, and a second contact face and a third contact face that are situated at opposite ends of the plurality of contact pins in the circumferential direction of the second mount, and that have substantially same distance to the second mount center line.