What is the fine-grained topic of the following text: YOKOHAMA, Japan — February 10, 2015 – Sigma Corporation of America, a leading researcher, developer, manufacturer and service provider of some of the world's most impressive lines of lenses, cameras and flashes, today announced the new Sigma 24mm F1.4 DG HSM Art lens, the ninth Global Vision lens to join the company’s iconic Art line-up. Only return the topic.
Announcement of the new Sigma 24mm F1.4 DG HSM Art lens by Sigma Corporation of America