This is a much sought-after Pentac Air Ministry lens with a focal length of 8 inches and a large maximum aperture of f/2.9. It is perfect for wet collodion and other alternative photographic processes that require a fast lens.

The lens is marked NOC (National Optical Company). These lenses were built for the RAF in WW II for reconnaissance on board of aircraft. The lens is a triplet like the Voigtlander Heliar. However its f/2.9 aperture gives a very shallow depth of field which is comparable with the f/2.5 Kodak Aero lens. As a result, the Pentac is known for its nice "bokeh" (the quality of the out of focus areas). The lens is uncoated and will provide nice highlights but less contrast than modern lenses; you will most likely want to address that by fashioning a lens shade for it.

The lens will cover 4x5 inch at close portrait distances. It is a quality optic - many of these were made by Dallmeyer and Taylor Taylor Hobson for the Air Ministry but are not branded as such.