Nauticam once again demonstrates its commitment to underwater photographers with the introduction of the Mid-range Focus Optimizer 3-II (MFO-3II). As full-frame mirrorless cameras become the go-to choice for serious underwater imaging, a key limitation has emerged: the lack of close-focusing, wide-angle macro lens options—especially for blackwater photography. The MFO-3II is designed to solve that problem without requiring new camera lenses or ports. Optimized for use with longer focal length full-frame macro lenses (such as 90mm, 100mm, and 105mm), the MFO-3II transforms these lenses into an approximate 60mm equivalent. It also delivers significantly enhanced "focus-to-the-glass" performance while still offering ample working distance when needed. Whether you're capturing thumbnail-sized nudibranchs or grapefruit-sized frogfish, this water-contact optic delivers outstanding image quality—without the need to swap out your camera lens or port. While it's an outstanding tool for blackwater, the MFO-3II is just as capable in a wide range of macro environments. And despite its larger physical size, it actually boasts a lower in-water weight than the SMC-3, making it easier to handle and balance in the water. Mid-range Focus Optimizer 3-II (MFO-3II) Specifications Dimensions OD 84mm x H 114.2mm Weight in air 602g Buoyancy in water Negative 120g Max Magnification (*1) 0.9x Lens FOV/Converted FOV 23° / 38° Working distance (*1) 0-1500mm Body construction Hard-anodized aluminum alloy Lens construction 4 elements in 3 groups Lens coatings Anti-reflection Coating Mount thread diameter M67 Depth rating 100m *1 Tested with Nikon Nikkor Z MC 105mm f/2.8 VR S Macro Lens Compatibility Chart split Comparison with MFO-1 and SMC-3 81503 MFO-3 81501 MFO-1 81203 SMC-3 Dimensions(OD x H mm) Ø 84 x 114.2mm Ø 70 x 26mm Ø 70 x 32mm Weight in air 602g 218g 307g Buoyancy in water Negative 120g Negative 150g Negative 215g Lens FOV/Converted FOV(*1) 23°/38° Max. Magnification (*1) 0.9X 1.2X 2.3X Working distance (*1) 0-1500mm 108-1005mm 46-98mm Lens construction 4 elements in 3 groups 3 elements in 2 groups 3 elements in 2 groups Lens coatings Anti-reflection Anti-reflection Anti-reflection Mount thread M67 M67 M67 Depth rating 100m 100m 100m *1. Tested with Nikon Nikkor Z MC 105mm f/2.8 VR S Macro lens Compatible Lenses with MFO-3 (more coming soon) Lens Sensor format Lens FOV. Max. Magnification Working distance Converted FOV. Canon RF 100mm f/2.8 L Macro IS USM FF 24° 0.9X 0-1490mm 40º Canon EF 100mm f/2.8L Macro IS USM FF 24° 0.9X 0-1490mm 40º Nikon NIKKOR Z MC 105mm f/2.8 VR S Macro FF 23° 0.9X 0-1500mm 38° Nikon AF-S VR Micro-NIKKOR 105mm f/2.8G IF-ED FF 23° 0.8X 5-1490mm 38° Nikon AF-S Micro NIKKOR 60mm f/2.8G ED DX 26.5° 0.5X 0-1500mm 45º Sony FE 90mm f/2.8 Macro G OSS FF 27° 0.8X 0-1500mm 45º Fujifilm GF 120mm f/4 Macro R LM OIS WR Medium Format 25.7° 0.9X 15-1500mm 43º Olympus M. Zuiko Digital ED 60mm f2.8 Macro M43 20° 0.5X 0-1500mm 33º OM System M.Zuiko Digital ED 90mm f/3.5 Macro IS PRO(Normal macro mode) M43 14° 0.7X 0-1480mm 23º Canon EF-S 60mm f2.8 Macro USM APS-C 24.5° TBD Panasonic Lumix S 100mm f2.8 Macro FF 24° TBD resources Compatible Lenses Included in the box Front and rear rubber caps Neoprene bag M67 Spacer ring for SMC/CMC Cleaning cloth
