Zorki's Soviet rangefinder — the 4K in M39/LTM for Leica-compatible film photography.
The Zorki 4K is a Soviet 35mm rangefinder camera from KMZ, one of the later variants in the Zorki rangefinder series. The Zorki cameras used the M39 Leica Thread Mount, making them compatible with Leica LTM lenses and Soviet Jupiter/Industar optics.
The Zorki 4K uses M39 (Leica Thread Mount) screw thread for lens coupling, includes a combined rangefinder/viewfinder, and provides a mechanical focal-plane shutter with multiple speed settings. The 4K designation indicates a specific variant with self-timer.
The Zorki 4K's LTM mount compatibility means it accepts all M39 lenses including Leica LTM glass, Soviet Jupiter and Industar lenses, and various third-party M39 optics. LTM adapters enable M-mount and modern mirrorless lens compatibility.
Test rangefinder coupling accuracy at multiple distances. Check shutter operation at all speeds — Zorki shutters often require CLA service after storage. Inspect viewfinder clarity. Test M39 coupling with a known lens.