Condition: Nice brass lens Petzval design made by C. Usener Berlin & New York. The lens has a focal lenght of about 300mm and has wide aperture of F4, it does cover 8×10 tightly. This beauty comes in a museum like condition. The brass comes with a nice patina and without major wear. The glass on the other hand is very good too, there are minimal cleaning marks and one air bubble, but there is no seperation, fungus or any big damage at all. The lens features a waterhouse slot and comes with a fitting stop. Its just a pleasure to hold this piece of history in the hands! History : Using the lens serial number: 9.173 the lens can be placed in the 1870ies period. This is one of the very very few Usener Lenses out there, especially in such a condition! The lens comes with a fitting flange and lenscap (not original). If you have any questions, feel free to ask. Look out for my other listings if youre interested in antique camera and wet plate equipment! Importent Note: This item comes from my private collection and is around 100 years old (antique). I try my best to describe all the faults and major damage which are relevant for the function of this item. The item “Very RARE! C. F. Usener Petzval Portrait Brass Lens 300mm F4 wet plate 8×10″ is in sale since Saturday, September 15, 2018. This item is in the category “Foto & Camcorder\Photographica\Objektive”. The seller is “inomine” and is located in Düsseldorf. This item can be shipped worldwide.