Tokusatsu (Japanese: 特撮とくさつ | lit. 'special photography' | shortened from Tokushu Satsuki jujutsu (Japanese: 特殊撮影技術 | lit. 'special effects technology') is a Japanese term for live-action films or television programs that make heavy use of practical special effects. Credited to special effects director Eiji Tsuburaya, tokusatsu mainly refers to science fiction, war, fantasy, or horror media featuring such technology but is also occasionally dubbed a genre itself. Its contemporary use originated in the Japanese mass media around 1958 to explain special effects in an easy-to-understand manner and was popularized during the "first monster boom" (1966-1968). Prior to the monster boom, it was known in Japan as Tokushu gijutsu (Japanese: 特殊技術 | lit. 'special technology' | or shortened Tokugi | Japanese: 特技 | lit. 'special skill'). Renowned subgenres of tokusatsu include kaiju such as the Godzilla and Gamera series; superheroes such as the Kamen Rider and Metal Hero series; and mecha like Giant Robo and Super Robot Red Baron. Some tokusatsu television programs combine several of these subgenres, for example, the Ultraman and Super Sentai series. Tokusatsu is one of the most popular forms of Japanese entertainment, but only a small proportion of tokusatsu films and television programs are widely known outside of Japan. Nevertheless, certain properties have attained popularity outside of Japan; Godzilla is featured in popular American-made movies, and the Super Sentai Series was adapted into the Power Rangers series and broadcast internationally beginning in 1993.