Nikon Corporation (株式会社ニコン, Kabushiki-gaisha Nikon?) listen (help·info) (TYO: 7731), also known as just Nikon, is a Japanese multinational corporation headquartered in Tokyo, Japan, specializing in optics and imaging. Its products include cameras, binoculars, microscopes, measurement instruments, and the steppers used in the photolithography steps of semiconductor fabrication, of which it is the world's second largest manufacturer. The companies held by Nikon form the Nikon Group. Among its products are Nikkor imaging lenses (for F-mount cameras, large format photography, photographic enlargers, and other applications), the Nikon F-series of 135 film SLR cameras, the Nikon D-series of digital SLR cameras, the Coolpix series of compact digital cameras, and the Nikonos series of underwater film cameras. Nikon's main competitors in camera and lens manufacturing include Canon, Casio, Kodak, Sony, Pentax, Panasonic, Fujifilm and Olympus.