1. A system for automatically adjusting a focus setting of at least one imaging device on an imaging set, the system comprising: two or more tracking markers, each tracking marker comprising an identification means and a tracking pattern, the two or more tracking markers configured for attaching to the at least one imaging device and to corresponding one or more subjects to be imaged on the imaging set by the at least one imaging device; a first tracker disposed proximate the imaging set to gather first image information of the imaging set, the first tracker having a field of view including the at least one imaging device and the one or more subjects; a controller configured for receiving the first image information from the first tracker and for communicating to the at least one imaging device control signals for the adjusting of focus settings for the at least one imaging device based on distances between the at least one imaging device and the one or more subjects; and a database comprising predetermined information about the two or more identities and two or more tracking patterns of the corresponding two or more tracking markers.