Pentacon auto 50mm f/1.8
The Pentacon auto 50mm f/1.8 is a 50mm f/1.8 manual-focus lens for the M42 mount, made by Pentacon from 1960s-1990. It uses 6 elements / 5 groups, Double Gauss (Meyer Oreston derivative). Typical used value is $20 to $90, with most examples near $45, and it adapts to Sony E, Fuji X, MFT, Canon RF, Nikon Z, and L-mount with a plain mechanical adapter.
Pentacon auto 50mm f/1.8 specifications
Pentacon auto 50mm f/1.8 specifications
Why collectors want it
An inexpensive and plentiful East German fifty derived from the Meyer-Optik Oreston. The 15-blade multi-blade aperture gives smooth round bokeh that collectors like. Optical quality is good stopped down and it is a common budget adapting lens.
Mount and adapters for the auto 50mm f/1.8
The Pentacon auto 50mm f/1.8 has a native M42 mount. M42 is a 42mm x 1mm screw thread with a 45.46mm register, introduced in 1949 on the Contax S and later adopted by Praktica, Asahi Pentax, Fujica, Zenit, Yashica, and Chinon. Every mirrorless mount has a shorter register than 45.46mm, so a plain mechanical adapter puts the lens at its design distance and infinity focus is preserved. Plain threaded adapter, no optics. Lenses with an auto-diaphragm pin need either an Auto/Manual switch on the lens or an adapter with an inner flange that holds the pin in. Preset lenses such as the Helios 44-2 have no pin and work on any adapter.
| Camera system | Adapter | Infinity focus | Frames like | Guide |
|---|---|---|---|---|
| Sony E | Plain mechanical, 27.46mm | Yes | 50mm on full frame; 75mm on APS-C (1.5x) | M42 to Sony E |
| Fuji X | Plain mechanical, 27.76mm | Yes | 75mm on APS-C (1.5x) | M42 to Fuji X |
| MFT | Plain mechanical, 26.21mm | Yes | 100mm on Four Thirds (2x) | M42 to MFT |
| Canon RF | Plain mechanical, 25.46mm | Yes | 50mm on full frame; 80mm on APS-C (1.6x) | M42 to Canon RF |
| Nikon Z | Plain mechanical, 29.46mm | Yes | 50mm on full frame; 75mm on APS-C (1.5x) | M42 to Nikon Z |
| L-mount | Plain mechanical, 25.46mm | Yes | 50mm on full frame; 75mm on APS-C (1.5x) | M42 to L-mount |
Frequently asked
What mount is the Pentacon auto 50mm f/1.8?
The Pentacon auto 50mm f/1.8 has a native M42 mount. M42 is a 42mm x 1mm screw thread with a 45.46mm register, introduced in 1949 on the Contax S and later adopted by Praktica, Asahi Pentax, Fujica, Zenit, Yashica, and Chinon. 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 Pentacon auto 50mm f/1.8 worth in 2026?
A used Pentacon auto 50mm f/1.8 typically sells for $20 to $90, with most clean working examples near $45. Basis: eBay sold listings, 2024-2025. This is an estimate, not an appraisal; condition, variant, and service history move the number.
Does the Pentacon auto 50mm f/1.8 work on Sony E, Fuji X, and MFT?
Yes. M42 has a 45.46mm register and every mirrorless mount is shorter (16mm to 20mm), so a simple M42 adapter reaches infinity with no optics. On a full-frame body the Pentacon auto 50mm f/1.8 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, no optics. Lenses with an auto-diaphragm pin need either an Auto/Manual switch on the lens or an adapter with an inner flange that holds the pin in. Preset lenses such as the Helios 44-2 have no pin and work on any adapter.
When was the Pentacon auto 50mm f/1.8 made?
Pentacon made the auto 50mm f/1.8 from 1960s-1990. That puts the Pentacon auto 50mm f/1.8 11 years into the life of the M42 mount, which appeared in 1949 on the Zeiss Ikon Contax S (Dresden).
What is the optical design of the Pentacon auto 50mm f/1.8?
The Pentacon auto 50mm f/1.8 uses 6 elements / 5 groups, Double Gauss (Meyer Oreston derivative). Double Gauss designs are near-symmetrical six- or seven-element formulas that support fast apertures with good correction; fast versions show glow from spherical aberration and swirl from mechanical vignetting wide open.
Which lenses are similar to the Pentacon auto 50mm f/1.8?
Close alternatives in the same focal class are the Carl Zeiss Jena Pancolar 50mm f/1.8 (50mm f/1.8, $70 to $260), the Konica Hexanon AR 50mm f/1.7 (50mm f/1.7, $40 to $150), and the KMZ Jupiter-8 50mm f/2 (50mm f/2, $30 to $120). The Konica Hexanon AR 50mm f/1.7 is faster.
Alternatives to the auto 50mm f/1.8
Lenses within 15mm of 50mm from other makers, ranked by how close they sit in focal length, aperture, and price.
Side-by-side comparisons
- Pentacon auto 50mm f/1.8 vs Canon FD 50mm f/1.4 S.S.C.
- Pentacon auto 50mm f/1.8 vs Carl Zeiss Jena Pancolar 50mm f/1.8
- Pentacon auto 50mm f/1.8 vs KMZ Industar-61 L/Z 50mm f/2.8
- Pentacon auto 50mm f/1.8 vs KMZ Jupiter-8 50mm f/2
- Pentacon auto 50mm f/1.8 vs Konica Hexanon AR 50mm f/1.7
- Pentacon auto 50mm f/1.8 vs Leica Summicron-R 50mm f/2
- Pentacon auto 50mm f/1.8 vs Minolta MD Rokkor 50mm f/1.4
Where this lens fits
Appears in these lists
Terms this lens demonstrates
Related guides
- M42 to Sony EHow M42 screw-mount lenses work on Sony E cameras: the 27.46mm adapter, flanged versus flangeless rings, auto-aperture pins, camera settings, and the APS-C crop.
- Buying checklistA step-by-step checklist for buying used manual lenses: the flashlight test for fungus, haze, and separation, mechanical checks, seller language, grades, and mount traps.