Mid-range Focus Optimizer 3 (MFO-3)

Nauticam once again demonstrates its commitment to underwater photographers with the introduction of the Mid-range Focus Optimizer 3 (MFO-3). 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-3 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-3 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-3 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 (MFO-3) 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