The FR-1 provides superb close-focus performance from 3ft (91cm) to Infinity. It delivers the telescopic performance for which Questar is famed. The FR-1 is designed for accuracy and performance. It utilizes the Questar MKIII precision tube assembly design. There are no spacers, extenders, or diopters required. The FR-1 tube design allows for extended internal focus travel to accommodate this wide focus range. Focus is smooth and stable. The MKIII barrel design allows for integration of additional options such as motorized focus and future upgrade to SZ 83000 series. The improved boresight accuracy of this instrument provides greater accuracy in alignment applications. Equipped with a C-mount adapter and camera coupling set, this unit is ready to attach to any CCD camera with a standard C-thread, and the flexibility to be useful in virtually any situation.