12.5" (317mm) f/6 AO Cooke Triplet Configuration Lens 5x7, 5x8, Full Plate
This 12 1/2" (317mm) lens is in Very Good condition. The lens elements are clean, without fungus, haze or scratches, but may have some light cleaning marks or light internal dust. The focus adjustment works smoothly. The elements are arranged in a Cooke Triplet configuration of three elements in three groups. The dimensions of the lens is 4.08
inches (103mm) long. The inner barrel is 2.62 inches (66.5mm) wide. The outer barrel is 3.1 inches (79mm) wide. The visible portion of the front and rear
elements are both 2.35 inches (60mm) wide. The lens comes with a felt-lined metal lens cap and a lens board retaining ring. The lens board opening will need to be 3 inches (76mm). The circle of illumination is over 11 inches, which will cover 4x5, 5x7, 5x8 and full plate formats wide open and focused at infinity with room for movement.
This lens is be coated and appears to be corrected for aberrations. When used with an open aperture the depth of field is narrow and creates a nice aesthetically
pleasing smooth bokeh in the out of focus areas. This lens will be ideal for landscapes, portraits as well as still lifes using silver based and alternative processes.