An adapter for automatic-diaphragm M42 lens mount interchangeable lenses for Praktica and Pentax was available as an accessory for photographers migrating from the earlier system.

A mechanical connector was added to the QBM lens mount to enable the fully-automatic aperture; some early lenses for the SL35 lacked this additional interface and must be stopped down to meter with newer bodies.

These used a visibly different body based on the earlier Icarex 35S / SL 706 design but with plastic top and baseplates and offered nothing technologically radical.

[6] A rebadged version of the SL35M was sold as the Voigtländer VSL 1,[7][8] which was offered with both M42 and QBM lens mounts.

[11] The SL35 line was discontinued in the early 1980s,[5] but the QBM lens mount continued with the Rolleiflex SL2000F, a camera system that accepted interchangeable film magazines and was equipped with dual viewfinders (waist-level and eye-level), similar in concept to professional system SLRs like the Rollei SL66 and Hasselblad, scaled down for 135 film.

[14] A whole range of lenses were made for the QBM interchangeable lens mount system fitted to the Rolleiflex SL35 and Voigtländer VSL series cameras.

Lens brands manufactured for the QBM system included German-made Carl Zeiss, Rollei, Rolleinar, Schneider, and Voigtländer.