Leica 5cm (50mm) f/2 Summitar Collapsible Screw Mount Lens {A36 Clamp-On}

Leica Summitar 50mm f/2: the collapsible classic that defined an era.

The Summitar 5cm f/2 sits in the lineage of Leica's mid-century 50mm lenses, produced during the postwar decades when the collapsible barrel design was a practical solution for compact carry. The barrel collapses into the body, keeping a loaded camera slim enough for a coat pocket, a feature film photographers relied on before modern zoom lenses changed the calculus entirely. The LTM/M39 screw mount connects to a wide range of rangefinder bodies, and with the right adapter, it pairs with modern mirrorless systems for anyone shooting digitally.

At f/2, the Summitar delivers the rendering characteristics that define its era: a particular softness wide open that transitions to genuine sharpness as you stop down, with a drawing quality distinct from modern aspherical designs. Filter attachment uses an A36 clamp-on system than a threaded ring, a period-correct detail that reflects exactly when this lens was built. For anyone working with Leica M cameras via LTM adapter, or shooting on a Barnack-era body, the mount integration is direct and tactile in a way that modern bayonet systems simply aren't.

Who It's For

Film photographers shooting on Barnack-era or thread-mount Leica bodies get a native 50mm f/2 with no adapters needed and a collapsible profile that keeps the whole kit genuinely pocketable. Digital shooters using Sony E-mount or Micro Four Thirds bodies with a LTM adapter can access the Summitar's mid-century optical rendering for portrait and street work where the wide-open character is a deliberate creative choice. Collectors building a chronological Leica lens set will find the Summitar occupies a specific and important position between the Elmar era and the Summicron's arrival.

Key Features

• 50mm f/2 fixed focal length on Leica Thread Mount screw mount
• Collapsible barrel design for compact rangefinder carry
• A36 clamp-on filter attachment system
• Classic Summitar optical formula with era-specific rendering
• Manual focus with direct mechanical integration

FAQ

What mount is this, and will it work on my camera?

Leica Thread Mount (LTM/M39) screw mount - standard on Barnack-era Leica bodies and rangefinders from that era. It adapts to modern Leica M cameras with an LTM-to-M adapter, and to mirrorless systems with step-ring adapters, though rangefinder focusing requires manual RF patch alignment or external rangefinder coupling.

How do I attach filters to this lens?

A36 clamp-on system, not threaded. Period-correct design that clamps a 36mm filter directly to the barrel - no filter rings or adapters.

What's the optical performance like?

Wide open at f/2 you'll see the era's characteristic softness with beautiful falloff. Stop down to f/4 or f/5.6 and sharpness improves noticeably across the frame. The rendering is distinctly different from modern designs - smoother, less edge contrast, with a drawing quality that works well for portraiture and available light work on film.

Does it collapse?

Yes. The barrel collapses into the body for compact carry, then extends when you're ready to shoot. This was practical for pocket-sized rangefinder systems before zoom lenses became standard.

Can I use this on digital?

Yes, with adapters. LTM to Leica M for digital M cameras, or step-ring adapters for mirrorless. Focusing is fully manual; there's no autofocus or electronic aperture coupling on this vintage design.

Is this a single-coated or multi-coated element?

Summitar optics from this era typically feature single or early multi-coating. Expect some internal reflections and flare characteristics typical of postwar film-era glass - manageable with a lens hood but part of the rendering.