Olympus is a Japanese manufacturer of camera bodies, lenses, and accessories among other products, headquartered in Tokyo, Japan. Though initially limited to manufacturing medical equipment like microscope and endoscope, Olympus incorporated cameras into their fold in 1936. The Pen series cameras followed in 1959.
Olympus is credited with the development of the four-thirds system. A system that was designed specifically for digital photography. The system was strengthened by other manufacturers, chiefly Panasonic, as well as Sony and Fujifilm.
Early in 2017, Olympus stopped manufacturing lenses for the legacy four-thirds system. However, the spin-off of the system, the micro four-thirds system is alive and kicking with the launch of new camera models and lenses. Other manufacturers are also contributing to the M4/3 system. It is a dedicated mirrorless system that uses the four-thirds sensor sans the reflex mirror.