Lentar 135mm f2.8 camera lens M42 screw mount, 8-blade preset ap

This is a 135mm f2.8 Lentar lens with an M42 screw mount and coated optics, and an 8-blade preset aperture. It is marked Made in Japan on the base. Lentar branded lenses were distributed by the US based Lenco Photo Products, Inc., initially from Detroit Michigan, and sold as early as 1947. This appears to be an early variant because it is a "LENTAR", not an "AUTO LENTAR" or TELE LENTAR like later issues, the thread is labeled "CS" for Contax screw mount, the first camera to use the M42 mount, and the barrel has a leatherette barrel finish. Like most US lens distributors, rebranded lens were purchased from various Japanese manufacturers of various quality. This example is quite good with warm colors. There are some specs of dust inside, but the glass is otherwise clean with no haze, fungus, or scratches. The iris looks like it has some lubricant on the blades, but it is response and buttery smooth. The detachable metal hood is slightly dented, but it does its job. Preset apertures have two aperture rings; a clicked maximum preset ring, and a clickless aperture control, making this an ideal lens for cinematography.