Abstract: An optic support arm, which in one aspect of the invention comprises: a main support bracket having a first end and a second end, a follower guide post having a threaded bore therethrough, an elongated threaded member in threaded engagement with the threaded bore of the follower guide post, such that rotation of the threaded member causes linear movement of the threaded member relative to the main support bracket, a follower member connected at one end of the threaded member, and carried by the threaded member during linear movement of the threaded member in a direction toward or away from the first end of the main support bracket for releasably engaging a support member between the follower member and the first end of the main support bracket, a connecting member releasably connectable to the second end of the main support bracket, and a mounting mechanism supported by the connecting member.