KMZ Jupiter-8 50mm f/2
The KMZ Jupiter-8 50mm f/2 is a 50mm f/2 manual-focus lens for the M39 (Leica screw) mount, made by KMZ from 1950s-1980s. It uses 6 elements / 3 groups, Sonnar. Typical used value is $30 to $120, with most examples near $60, and it adapts to Sony E, Fuji X, MFT, Canon RF, Nikon Z, and L-mount with a plain mechanical adapter.
KMZ Jupiter-8 50mm f/2 specifications
Why collectors want it
A compact Sonnar-formula rangefinder fifty copied from the prewar Zeiss Sonnar. It renders with lower contrast and a classic vintage look wide open. It adapts to mirrorless via M39 to E or similar and is one of the cheapest ways into Sonnar rendering.
Mount and adapters for the Jupiter-8 50mm f/2
The KMZ Jupiter-8 50mm f/2 has a native M39 (Leica screw) mount. M39, the Leica thread mount (LTM), is a 39mm x 26 tpi screw thread with a 28.8mm register used on Leica, FED, Zorki, and Canon rangefinders. Every mirrorless mount has a shorter register than 28.8mm, so a plain mechanical adapter puts the lens at its design distance and infinity focus is preserved. Plain threaded adapter for mirrorless, no rangefinder coupling needed. A helicoid adapter adds close focus below the 1m rangefinder minimum. Do not confuse with the Zenit SLR M39 mount, which uses the same thread at a 45.2mm register.
| Camera system | Adapter | Infinity focus | Frames like | Guide |
|---|---|---|---|---|
| Sony E | Plain mechanical, 10.8mm | Yes | 50mm on full frame; 75mm on APS-C (1.5x) | M39 to Sony E |
| Fuji X | Plain mechanical, 11.1mm | Yes | 75mm on APS-C (1.5x) | M39 to Fuji X |
| MFT | Plain mechanical, 9.55mm | Yes | 100mm on Four Thirds (2x) | M39 to MFT |
| Canon RF | Plain mechanical, 8.8mm | Yes | 50mm on full frame; 80mm on APS-C (1.6x) | M39 to Canon RF |
| Nikon Z | Plain mechanical, 12.8mm | Yes | 50mm on full frame; 75mm on APS-C (1.5x) | M39 to Nikon Z |
| L-mount | Plain mechanical, 8.8mm | Yes | 50mm on full frame; 75mm on APS-C (1.5x) | M39 to L-mount |
Frequently asked
What mount is the KMZ Jupiter-8 50mm f/2?
The KMZ Jupiter-8 50mm f/2 has a native M39 (Leica screw) mount. M39, the Leica thread mount (LTM), is a 39mm x 26 tpi screw thread with a 28.8mm register used on Leica, FED, Zorki, and Canon rangefinders. With a plain mechanical adapter it fits Sony E, Fuji X, MFT, Canon RF, Nikon Z, and L-mount bodies and keeps infinity focus.
How much is the KMZ Jupiter-8 50mm f/2 worth in 2026?
A used KMZ Jupiter-8 50mm f/2 typically sells for $30 to $120, with most clean working examples near $60. Basis: eBay sold listings, 2024-2025. This is an estimate, not an appraisal; condition, variant, and service history move the number.
Does the KMZ Jupiter-8 50mm f/2 work on Sony E, Fuji X, and MFT?
Yes. M39 has a 28.8mm register and every mirrorless mount is shorter (16mm to 20mm), so a simple M39 adapter reaches infinity with no optics. On a full-frame body the KMZ Jupiter-8 50mm f/2 frames as a 50mm lens; on APS-C (1.5x) it frames like a 75mm, on Canon APS-C (1.6x) like a 80mm, and on Micro Four Thirds (2x) like a 100mm. Plain threaded adapter for mirrorless, no rangefinder coupling needed. A helicoid adapter adds close focus below the 1m rangefinder minimum. Do not confuse with the Zenit SLR M39 mount, which uses the same thread at a 45.2mm register.
When was the KMZ Jupiter-8 50mm f/2 made?
KMZ made the Jupiter-8 50mm f/2 from 1950s-1980s. That puts the KMZ Jupiter-8 50mm f/2 20 years into the life of the M39 mount, which appeared in 1930 on the Leica I (Model C), standardized in 1931.
What is the optical design of the KMZ Jupiter-8 50mm f/2?
The KMZ Jupiter-8 50mm f/2 uses 6 elements / 3 groups, Sonnar. Sonnar designs pack their elements into thick cemented groups with few air-to-glass surfaces, which gave high contrast before multi-coating and a smooth, low-contrast look wide open.
Which lenses are similar to the KMZ Jupiter-8 50mm f/2?
Close alternatives in the same focal class are the Leica Summicron-R 50mm f/2 (50mm f/2, $350 to $900), the Pentacon auto 50mm f/1.8 (50mm f/1.8, $20 to $90), and the Carl Zeiss Jena Pancolar 50mm f/1.8 (50mm f/1.8, $70 to $260). The Pentacon auto 50mm f/1.8 costs less on the used market. The Pentacon auto 50mm f/1.8 and The Carl Zeiss Jena Pancolar 50mm f/1.8 are faster.
Alternatives to the Jupiter-8 50mm f/2
Lenses within 15mm of 50mm from other makers, ranked by how close they sit in focal length, aperture, and price.
Side-by-side comparisons
- KMZ Jupiter-8 50mm f/2 vs Carl Zeiss Jena Pancolar 50mm f/1.8
- KMZ Jupiter-8 50mm f/2 vs KMZ Industar-61 L/Z 50mm f/2.8
- KMZ Jupiter-8 50mm f/2 vs Konica Hexanon AR 50mm f/1.7
- KMZ Jupiter-8 50mm f/2 vs Leica Summicron-R 50mm f/2
- KMZ Jupiter-8 50mm f/2 vs Minolta MD Rokkor 50mm f/1.4
- KMZ Jupiter-8 50mm f/2 vs Pentacon auto 50mm f/1.8