🔘 6-Bit Flange Adapter Ring – Zeiss ZM Lenses (21/28mm & 50mm)
Precision 6-bit coded replacement flange ring for select Zeiss ZM lenses. Allows your Leica M digital camera to automatically detect your lens for EXIF data and in-camera corrections. ⚠️ Only 3 out of 4 screw holes line up – the 4th screw hole is in the position of the 6-bit pits.
🔧 Material: Precision-machined brass (chromed silver) – durable, exact fit.
🔧 About the 4th Screw Hole:
On the original Zeiss ZM flange, one screw hole is positioned exactly where the 6-bit coding pits need to be milled. This replacement flange uses only 3 screws to secure the lens – the 4th hole is intentionally omitted to make room for the 6-bit code. This is normal and will not affect lens stability when properly installed. Many photographers have successfully used 3-screw mounts on ZM lenses for years.
✅ Variation 1 – Biogon 21mm f/2.8 & Biogon 28mm f/2.8
  • Compatible lenses: Zeiss ZM Biogon 21mm f/2.8, Zeiss ZM Biogon 28mm f/2.8
  • Frameline activation: Brings up 28/90mm framelines
  • Recommended Leica code: 21mm f/2.8 ASPH (for 21mm) or 28mm f/2.8 (for 28mm)
  • Screw holes: 3 out of 4 align – 4th omitted for 6-bit pits
✅ Variation 2 – Sonnar 50mm f/1.5 & Planar 50mm f/2
  • Compatible lenses: Zeiss ZM C Sonnar 50mm f/1.5, Zeiss ZM Planar 50mm f/2
  • Frameline activation: Brings up 50/75mm framelines (correct for 50mm lenses)
  • Recommended Leica code: 50mm f/1.4 Summilux ASPH (for Sonnar) or 50mm f/2 Summicron (for Planar)
  • Screw holes: 3 out of 4 align – 4th omitted for 6-bit pits
📩 Need a flange for other Zeiss ZM lenses?
Message me with your lens model (e.g., 25mm, 35mm, 85mm) – I may have 6-bit rings available or can create custom orders.
🎨 6-Bit Painting Service – Available for a Fee

The flange comes with precision-milled 6-bit pits, but the pits are empty (no paint). For the 6-bit code to be read by your Leica camera, the pits need to be filled with matte black paint (and optionally white for the screw hole).

I offer a professional painting service for an additional fee. Message me for pricing and details.

🚚 Shipping & Returns
📦 Fast handling
✅ Tracked shipping
🔄 30-day returns (buyer pays return shipping unless defective)
🔘 Sold by jinfinance (R.J.) — 20+ years experience. Questions? Message me.
✉️ For 6-bit painting service pricing, other ZM lenses, or custom orders – message me for details.