Schneider's large format process lens — the G-Claron 210mm for macro and repro photography.
The Schneider G-Claron 210mm f/9 is a process (copy) and large format photography lens from Schneider-Kreuznach, Germany. The G-Claron designation indicates a lens optimised for reproduction at 1:1 to 1:5 magnification ratios — making it a specialist optic for document reproduction, technical copying, and also large format photography where its flat-field correction is advantageous.
The lens delivers 210mm at f/9 maximum aperture with Schneider's process-lens optical design featuring excellent flat-field correction and minimal distortion, a Copal or Compur shutter (common in large format use), and coverage suited to 5x4 inch or larger formats. The modest f/9 aperture is typical for process lenses where diffraction limits faster apertures at macro ratios.
The G-Claron is valued in large format photography for its compact size relative to coverage, precise flat-field rendering, and low distortion. At the reproduction ratios it was designed for, it outperforms many standard large format lenses. It is popular among large format photographers and technical reproduction specialists.
Test shutter operation across all speeds if in a Copal or Compur shutter. Inspect element quality for coating integrity and freedom from fungal spotting. Verify coverage circle for the intended negative size. Check for any shutter timing inaccuracy using a shutter speed tester or audio method.