Four Thirds

转接环只能增加镜头与胶片之间的距离，无法缩短。这些卡口比 Four Thirds 更靠近胶片，因此原则上其镜头可以转接上去并仍能合焦无限远。没有记录法兰距的卡口不列出，而不是靠猜。

• Sony 1/2" TV bayonet mount 38 mm
• Panavision SP70-mount 38 mm
• Alpa 35mm bayonet 37.8 mm
• Minolta V-mount 36 mm
• 1/2" TV bayonet mount 35.74 mm
• Contax rangefinder mount (Contax/Kiev) 34.85 mm
• Nikon S-mount 34.85 mm
• Hasselblad XPan 34.27 mm
• Kiev-16U 31 mm
• Robot M26×0.5 screw mount 31 mm
• Contax G-mount 29 mm
• Olympus Pen F bayonet (half-frame) 28.95 mm
• Meopta Opema 38 mm screw 28.8 mm
• Narciss M24×1 screw mount 28.8 mm
• Leica thread mount (M39×26 tpi, LTM) 28.8 mm
• Leica M-mount 27.8 mm
• Chaika M39 half-frame thread (27.5 mm) 27.5 mm
• RED ONE interchangeable mount 27.3 mm
• Pentax 110 27 mm
• Fujifilm G-mount 26.7 mm
• Samsung NX-mount 25.5 mm
• JVC 1/3" bayonet mount 25 mm
• L-Mount 20 mm
• Canon RF mount 20 mm
• Micro Four Thirds 19.25 mm
• Sony FZ-mount 19 mm
• Hasselblad XCD mount 18.14 mm
• Sony E-mount 18 mm
• Canon EF-M mount 18 mm
• Fujifilm X-mount 17.7 mm
• C-mount 17.53 mm
• Nikon 1-mount 17 mm
• DJI DL-mount 16.84 mm
• Nikon Z-mount 16 mm
• CS-mount 12.53 mm
• D-mount 12.29 mm
• M58×0.75 mm mount 12 mm
• Pentax Q-mount 9.2 mm
• Samsung NX-M (NX mini) 6.95 mm