The Kirk FR-2 Focusing Rail is a precise focusing stage designed to permit fine tuning of camera-to-subject positioning in order to achieve exacting focus. The rail is driven by a 4.25" stainless steel lead screw, with a pitch of 5/16"-24, that enables critical positioning at a rate of 0.042" per revolution. Fine focusing is controlled by one of two knobs located at the ends of the rail or, for larger adjustments, a stage release lever permits faster, less restricted movement.
Mounted atop the focusing rail is a 2.5" quick release mount, which can rotate up to 360° in 90° intervals. This mount accepts Arca-style quick release plates for easily attaching both cameras and collared lenses. Extending the entire base of the focusing rail is an Arca-style dovetail with three 1/4"-20 mounts also available.
All parts of the rail are CNC-machined from 6061TC aluminum alloy and stainless steel.