Designed for special low-light application like night photography, night television, star light photography, and image intensifier applications. Used by NASA on various projects. Designer was Dr. Tronnier, one of the German lens design experts employed by Farrand Corp., the company that produced these lenses in the 1960s and 1970s. [US Pat. No. 2846923 from 1958 (filed in 1957).] 

This lens listed at $5500 in 1965 (see Picture #13).

The lens covers 35mm format (40mm image circle, very slight corner cutoff) but must be mounted very close to the film or detector. The back focal distance is only 3mm.

The lenses have no F-stop diaphragm and no shutter. They were meant for scientific applications characterized by very low-light situations, where the lens was to be used fully open with longer exposure times (such as astronomical photography, spectrographic applications, upper atmosphere chemical releases, etc.).

F-stop Adjust:  The front and rear lens assemblies readily screw apart, and there is ample room to install an iris diaphragm shutter in between. However the main feature of this lens is its low aperture of 0.87, so it would seem to be at cross purposes to install an iris diaphragm.

Shutter:  The space could be used to install a shutter. You would probably need access to a machine shop to do this.

Focus: Focus is achieved by screwing the whole lens in/out on the mounting thread (80mm Diameter x 1mm pitch).

Examples of cameras using this lens are shown in Picture #11. 

Front lens diameter:                 90 mm

Rear Lens Diameter:                40 mm

Length:                                     115 mm

Weight:                                     3 lb. 4 oz

9 elements in 3 groups:

Image Diameter:                        40 mm

Field of View:                             30 deg.

Resolution @ f0.87:                   40 lp/mm

Coated optics, Spectral Range: 400-700 nm 

Optics:

The front and rear lens assemblies readily screw apart (useful for cleaning).  The rear lens assembly then screws apart into two sub-assemblies.  See Picture #12 for diagram.

The front and rear glass surfaces show no scratches or cleaning marks. Both lenses have very minor defects, not surprising in lenses of this age. I do not believe that either of these imperfections would have any significant effect on image quality. 

Serial No. 211:  A few tiny hairs on an internal surface, no scratches or fungus. Very slight browning of an internal element. Barrel has a minor scratch on outside near front. Generic front and rear lens caps.

Serial No. 323:  A few internal dust spots, no scratches or fungus. Extremely slight browning of an internal element. Barrel in mint condition. Generic front and rear lens caps.

Note: Some of these fast lenses from the 1960s-1980s used thorium glass, which over time led to browning of the glass. The level of radioactivity [alpha particles and/or beta particles] is very low and is zero a couple of feet from the lens, but buyers genuinely worried about the radioactivity possibility. These lenses have been tested with a geiger counter, and show zero counts, even right on the lens surface (see last Picture).