Who were the main figures involved in the introduction in 1892 of 35 mm film for still photography and motion pictures?

Question

Who perfected a process in 1880 for making sensitive gelatine dry plates for photography, and patented photographic roll film in 1884?

Answer 1

William Dickson, Thomas Edison & George Eastman
The standard introduced in 1892 is relatively unchanged since then. Its longevity is largely because the ubiquity of 35 mm movie projectors in commercial movie theatres makes it the only motion picture format, film or video, which can be played in almost any cinema in the world.