K. K. Cosina (Japanese株式会社 コシナ, Kabushiki - gaisha Kosina, Eng. Cosina Co., Ltd.. ) Is a Japanese manufacturer of optical equipment and a family in present second generation.

The product portfolio includes the manufacture of rangefinder cameras and lenses under the brand name Voigtländer in cooperation with ring and photo lenses under its own name.

In addition, Cosina has worked for other companies in contract manufacturing, such as in-camera production (Zeiss Ikon, Nikon FM10 ) and in the manufacture of lenses (series ZF, ZI, ZK, ZM for Zeiss in the 1970s for Ihagee, Contax S2)

Cosina in 1959 as K. K. Niko (株式会社 ニコー) founded and renamed 1973.