Explores the world of Macrophotography with your SLR 35mm camera or Medium format camera. 35mm SLR camera The Macro Explorer lenses are made to be used with any 35mm SLR camera interchangeable lenses in the range of 50mm to 300mm focal length. Medium Format Compatibility The MacroExplorer lenses work just as well on medium format SLR camera. 72mm and77mm adapter rings are optionally available for this purpose. Large Aperture Lenses Both the 1.5X and 2.5X Macro lenses are designed with large apertures for max. Light transmission. Wide-open apertures mean fast enough speeds even on overcast days. Why Two Macro Lenses. Two lenses are supplied to make available a full range of magnification. The lenses yield reproduction ratio from: 1: 4 (0.25X) to 2.7: 1.