Hello, this is a very rare Voightlander & Sohn Collinear III 31cm 310mm Brass Lens. Overall very good condition. There is some “crystallisation” on the corners of the glass (looks like golden dots). And some light scratches cleaning marks – please check the last 2 pictures. Otherwise the glass is clean – no fungus. The aperture (18 blades) movement is smooth. Please examine all pictures of actual item!