Pentacon 35-70mm f/3.5-4.5 — M42 standard zoom with macro switch for Praktica SLRs
The Pentacon 35-70mm f/3.5-4.5 was VEB Pentacon's own standard zoom for the Praktica SLR system, sold from the late 1970s into the 1980s as an alternative to buying separate 35mm and 50mm primes, part of East Germany's push to offer domestic zoom optics rather than imported Japanese glass.
Built with an automatic diaphragm and a macro switch that decouples the barrel from the zoom ring for close-up work, it was made in M42 screw mount for Praktica L-series bodies and later reworked with electrical contacts for the bayonet Praktica B system. Aperture falls from f/3.5 at 35mm to f/4.5 at 70mm.
Optically it favors moderate sharpness at the wide end over the corner performance of later Japanese standard zooms, with contrast softening past 60mm. The macro mode is a genuine practical extra rather than a marketing add-on, focusing closer than typical period zooms of its class.
These zooms are common and inexpensive used, often bundled with Praktica bodies rather than sold alone. Cycle the macro switch and zoom ring to check for stiffness or grease creep common in decades-old Pentacon helicoids, and confirm the aperture stays coupled through the zoom range.