
Kenko (company)

 is a Japanese manufacturer and trading company of photographic accessories, especially known for its teleconverters and filters. Located in Tokyo, it has been producing conversion lenses since the 1960s. It produces camera lenses under the Tokina brand name. It also manufactures a beginner's 35 mm SLR camera (using the Nikon F-mount) under the Kenko name.
Lenses.
For current Kenko teleconverters and lens extension rings see List of Nikon compatible lenses with integrated autofocus-motor (note that Canon EF versions also exist).