LEICA - leica IIIG rangefinder adjustments

Official Ernst Leitz GmbH technical service manual for rangefinder adjustment on the Leica IIIG (serial numbers 825 001 through 988 350). This four-sheet workshop documentation provides the complete procedure for precision tuning of the rangefinder coupling and alignment system. The manual opens with a full tools and instruments list, specifying precision screwdrivers in multiple sizes, graticule assemblies, lens mount components, distance setting gauges, and all specialized adjustment instruments required for the work. The operational sequence guides you through mounting and centering the rangefinder module to the camera body, then walks through three critical adjustment stages. Parallax compensation focuses on registering the 90 mm mark with the field frame using the distance setting gauge. Vertical error correction uses knurled screws to align the viewfinder frame with the graticule field frame. Lateral error correction employs the eccentric disc and distance setting screw to achieve index mark alignment across the full measuring range. A detailed technical illustration identifies the rangefinder coupling lever, eccentric disc, roller assembly, and all adjustment points. The manual concludes with sealing procedures, functionality verification checks, and complete camera assembly confirmation, ensuring the rangefinder performs to factory specification.