The BH2, from the high sales volume BH series, debuted in 1980s. The company developed the BH2 Series ahead of the AH2 Series, building a microscope that approached the optical performance of overseas products and provided even greater freedom in modular combinations.
The objective lens can be described as the heart of a microscope. Until the BH2 Series debut, microscopes tended to have short barrels, with a focal length of 36.65mm and a mechanical tube length of 160mm. Olympus then developed a long barrel (LB) objective lens series (1x–100x oil) with a focal length of 45mm and a mechanical tube length of 160mm that could be used for everything from regular bright field observations to polarization, fluorescence, and phase contrast microscopy. As a result, the BH2 Series captured the highest share of the global market. The company's main microscopy revenue stream was therefore on more solid ground.
In 1981, Olympus developed the IC Series featuring an LB objective lens for industrial applications and the universal vertical illuminator UMA for additional industrial applications. The company then developed further improved models for the BX and CX Series, utilizing a UIS objective lens.