Leitz SM Pol microscope was developed sometime during the mid-1960s. This earlier version of the triangular base had a rounded back for the SM as well as Labolux. SM or student models usually used a removable lamp holder or a mirror, each with a pin to fit a hole in the foot beneath the substage. “Lux” in the name indicates the light source is built into the base.
The company of Ernst Leitz has its origin in the Optical Institute founded by Karl Kellner in Wetzlar, Germany, in the late 1840s. Initially the main product produced was telescopes, but in the 1850s microscopes became the lead product. By the 1920s Leitz was a major manufacturer of scientific optical equipment, cameras (under the brand name Leica), and military optics, including bombsights and range finders.
Leitz produced polarizing microscopes after 1885, and by 1890 there was a specialized petrographic model in their catalog. Demand was enough for the first of many special catalogs for polarizing microscopes and accessories in 1893. By the 20th century, Leitz was using the “modern” style of microscope stands, with horseshoe feet and a curving limb to the tubular head, which continued until after the second world war. As did Zeiss and other companies during the 1950s and 60s, Leitz adopted newer styles of microscopes with rectangular hollow frames and feet, internal illumination systems, and modular (add-on) systems for phase contrast, dark field, polarization, photomicrography, and other methods. Like other makers at the time, Leitz used a durable glossy black baked-on enamel finish for most of their microscope models, until finally converting to light bluish-gray colors in the 1970s.
Today the company, formerly Ernst Leitz GmbH, exists as three independent companies: Leica Camera AG, which produces cameras; Leica Geosystems AG, which produces geosurvey equipment; and Leica Microsystems AG, which produces microscopes.