Bayonet mount and optical apparatus

摘要

The surface groove 26c formed in the circumferential direction has a configuration 26x producing a shallow groove. Thus, relative rotation during lens attachment is accomplished without obstruction, and the strength of the bayonet pawls is improved by the enhanced thickness of the center portion by the formation of a gradual angle formation toward the exterior side of cylinder wall 20 from both ends of the surface groove toward the center portion thereof. This type of surface groove configuration 26x is formed at the three surface grooves 26a, 26b, 26c.