Helping to realize accurate framing, this VarioFinder Mask is designed to be used in conjunction with the Arca-Swiss VarioFinder viewfinder for achieving a correct field of view based on the specific lens focal length and image sensor size/film format in use. This specific mask is designed for use with the 6 x 9 film format along with lenses with a focal length between 110mm and 210mm. The mask's slim metal design also permits moving and placing it within the finder's holder system to previsualize shift movements.