The Rodenstock 75mm F/4.5 Grandagon-N Lens is the ideal professional duplication solution to reduce distortion at a scale of 1:1. It is designed to be used in CCD cameras, macro photography, and the duplication of transparencies at a reproduction scale of around 1:1.The Rodenstock 75mm F/4 D Enlarging Lens is used in 35mm or 6 x 6 film duplicationThis Rodenstock Enlarger Lenses has a mount size of 39mm (retaining ring not included)For 6 x 6 duping the recommended scale size is 0.8 to 1.2x and for 35mm it is 0.7 to 1.5xDimensions: 2.08 x 1.9" (H X W)