A system comprising two camera lines and an extensive range of M42 screw-mount lenses, from ultra-wide angle to super telephoto and telephoto zooms. The J-series cameras had a mechanical shutter, and exposure metering was performed not through the lens, but using a special window exposure meter, which was either built into the camera or mounted additionally. Starting with the TL series, TTL exposure metering appeared, and most TL Electro models received an electronically controlled shutter. All cameras of the system performed stop down exposure metering. The Electro AX also added aperture priority automatic exposure metering.
All lenses feature automatic diaphragm, except for the R preset lenses and reflex lenses with fixed diaphragm. DS-M lenses are multi-coated, the rest are single-coated. Non-DX and R lenses were the earliest, while DS-M lenses were the last in production.
The actual manufacturer of these lenses was Tomioka Optical Works, one of the largest and most reputable lens manufacturers in Japan. The relationship between companies began already in 1953 (years before the introduction of Yashica's first 35mm film SLR camera with M42 screw mount), and in August 1968 the company was acquired by Yashica.