Adapter guide
Contax/Yashica lenses on L-mount
Yes, this works. Contax/Yashica has a 45.5mm flange distance and L-Mount Alliance (Leica, Panasonic, Sigma) has 20mm, so a 25.5mm mechanical adapter with no glass fills the gap and infinity focus is preserved. Focus and aperture stay manual.
- Contax/Yashica flange
- 45.5 mm
- L-mount flange
- 20 mm
- Adapter thickness
- 25.5 mm
- Optical elements
- None required
Setting it up
On Panasonic S bodies set Shoot w/o Lens to On and enter the focal length for stabilisation. Leica SL bodies accept adapted lenses without a setting change and Leica sells its own R-Adapter L for Leica R glass.
Automatic diaphragm. C/Y lenses sit at the set aperture when off the body, so the ring works directly on an adapter.
Contax/Yashica lenses and their field of view on L-mount
Effective focal length changes with sensor size. The lens itself does not change; the smaller sensor simply captures a narrower part of the image circle.
| Lens | Focal length | Aperture | Full frame | Frames like (APS-C (1.5x)) | Years | Used value |
|---|---|---|---|---|---|---|
| Carl Zeiss Distagon T* 28mm f/2.8 (C/Y) | 28mm | f/2.8 | 28mm | 42mm | 1975-2005 | $180 to $550 |
| Carl Zeiss Planar T* 50mm f/1.4 (C/Y) | 50mm | f/1.4 | 50mm | 75mm | 1975-2005 | $120 to $420 |
| Carl Zeiss Planar T* 85mm f/1.4 (C/Y) | 85mm | f/1.4 | 85mm | 128mm | 1975-2005 | $500 to $1,400 |
Frequently asked
Do Contax/Yashica lenses work on L-mount cameras?
Yes. A plain Contax/Yashica to L-mount adapter works with no optics. Contax/Yashica has a 45.5mm register and L-Mount Alliance (Leica, Panasonic, Sigma) has a 20mm register, so the adapter is a 25.5mm tube that puts the lens exactly where a Contax/Yashica body would. Plain adapter ring, no mechanism required. Zeiss and Yashica ML lenses share the mount and use the same adapter.
Do Contax/Yashica lenses focus to infinity on L-mount?
Yes. Because the adapter restores the native 45.5mm register, infinity focus is preserved and the full focus scale on the lens stays accurate. Adapters machined slightly short let the lens focus past infinity by a small margin, which is harmless; adapters machined long stop short of infinity, so buy from a maker with tight tolerances.
What focal length does a Contax/Yashica lens become on L-mount?
On full frame L-mount bodies (Leica SL series, Lumix S series, Sigma fp) the focal length is unchanged: a 28mm lens frames as a 28mm. On APS-C (1.5x) L-mount bodies (Leica CL, TL, TL2) a 28mm lens frames like a 42mm lens on full frame; the aperture and depth of field at a given distance do not change.
More on this mount: Contax/Yashica mount reference