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hkItem Name : G.Rodenstock Pantogonal No.5 25cm f18 ULF Brass Barrel Lens
Serial no. : 62289
Reference : Extremely Rare No.5 !!,Rodenstock factory article only mention produced no.1(8.5cm) to no.4(20cm),never mention no.5 exist, it may be special order, should cover 20x24in because 16.5cm already cover 12x20in,Pantogonal is the same design as the Goerz Hypergon, a very simple symmetrical lens with two elements, extraordinarily wide angle of 125 to 130 degrees enables these anastigmats to be used for plates the diagonal of which is times the focus of the lens. The relative aperture of f18 is sufficient for instantaneous exposures out of doors in favorable light. For time exposures, when the full angle is used, it is advisable to use the Enixantos Compensator which is furnished with the lens. This consists of a plano-convex lens of yellowish green glass which absorbs very strongly blue and violet light, and a plano-concave lens of a colorless, very transparent material. The optical constants of both these lenses is exactly equal so that the cemented lenses act as a plane parallel plate which is dark in the center and transparent at the sides. The effect of this is that the marginal rays which pass through the lens at great angle undergo only a slight absorption, and therefore any marked decrease of light toward the edges of the plate is prevented. Thus the necessity of bunglesome and complicated appliances usually found on extreme angle lenses is obviated. With orthochromatic plates the Compensator has the added advantage of giving excellent color values. The "Pantogonal" is guaranteed to be the finest wide-angle lens to be obtained at any price.
Glass Description : very very faint cleaning marks,no haze or separation
Remark :
Cosmetic Condition : EX+++
Price : $