Thypoch Eureka 50mm f/2

The Lens

The Thypoch Eureka 50mm f/2 is a standard prime lens released in 2024. Manufacturers designed the optic as a direct tribute to the collapsible lenses of the 1950s, specifically referencing the first-generation Leica Summicron. Although the lens maintains a vintage external profile, Thypoch re-engineered the internal optical system with modern glass types to ensure performance remains consistent on high-resolution digital cameras. The lens is notable for its availability in two distinct material finishes and its retractable barrel mechanism.

Optical Design and Performance

Internally, the Eureka utilizes a six-element, four-group optical structure based on the classic double-Gauss configuration. While the layout mimics the 1953 design it emulates, the inclusion of High Refractive Index (HRI) and Extra-Low Dispersion (ED) elements marks a significant departure from vintage manufacturing. This modern glass helps suppress chromatic aberration and improves overall sharpness compared to the original thorium-based optics.

The resulting image quality serves as a hybrid between old and new standards. At the maximum aperture of f/2, the lens retains a degree of spherical aberration. This optical characteristic creates the soft rendering or "glow" often associated with vintage photography. However, modern multi-coatings ensure the lens delivers significantly higher contrast and flare resistance than actual vintage lenses. A distinctive feature of this model is the 12-blade aperture diaphragm, which maintains a circular shape at all settings to produce smooth, non-polygonal background blur.

Mechanical Construction

Thypoch produces the Eureka in two variations that differ in weight and tactile handling:

• Aluminum Version: This model weighs approximately 120g (excluding caps). The lightweight construction prioritizes portability and handling on lighter camera bodies.
• Brass Version: This model weighs approximately 230g. The brass variant offers a dense, substantial feel that closely mirrors the experience of using historic Leitz equipment, though the optical performance is identical to the aluminum model.

The defining mechanical feature is the collapsible barrel, which allows the user to push the optical cell back into the camera body for compact storage. The design ensures the rear element generally clears the sensor stack of modern digital Leica M bodies, but users should still verify clearance to prevent accidental contact. The lens focuses down to a minimum distance of 0.9 meters, a slight improvement over the 1-meter standard of the original vintage inspiration.

Comparison to Alternatives

The Eureka occupies a specific niche for photographers seeking vintage character without the maintenance issues of antique glass.

Voigtländer Color-Skopar 50mm f/2.2

The Color-Skopar represents a strictly modern approach to compact lens design.

• Design: It features a rigid, non-collapsible barrel that is nonetheless extremely compact.
• Optics: The Skopar prioritizes clinical sharpness, high contrast, and neutral color rendering from the widest aperture. It does not exhibit the spherical aberration or "glow" found in the Eureka.
• Summary: The Skopar serves as a technical tool for maximum image fidelity, whereas the Eureka functions as an aesthetic choice for character and texture.

Light Lens Lab 50mm f/2 "Elcan"

The Light Lens Lab Elcan is a replica of a rare military optic originally manufactured by Leitz Canada.

• Construction: This lens uses a rigid, ultra-compact barrel and a simple four-element optical design.
• Rendering: The Elcan is famous for high center sharpness that falls off significantly towards the corners. The Eureka, with its six-element design, generally provides a more consistent field of focus across the frame.
• Positioning: The LLL Elcan typically commands a higher price point and targets collectors focused on historical accuracy.

Leica Summicron 50mm (V4 and V5)

The Version 4 and Version 5 Summicrons are widely considered the modern benchmarks for the 50mm focal length.

• Performance: These lenses offer superior micro-contrast and corner-to-corner sharpness. They produce a transparent, neutral image that lacks the specific optical aberrations intentionally preserved in the Eureka.
• Mechanics: These are rigid lenses that typically feature a focus tab (on the V4 and most V5 units), which allows for faster ergonomic operation compared to the classic focus ring and infinity lock found on the Eureka.

Leica Elmar 50mm f/2.8

The Elmar is the most common historical alternative for a collapsible lens.

• Aperture: The Eureka is a full stop faster (f/2) than the Elmar (f/2.8).
• Optical Formula: The Elmar utilizes a Tessar design, known for exceptional center sharpness but occasionally "busy" or nervous background blur. The double-Gauss design of the Eureka generally produces smoother transitions in out-of-focus areas.