Simplify the following text for a Grade 11 native English-speaking person.
Original: Sergei Mikhailovich Eisenstein ( ; January 23 , 1898 â `` February 11 , 1948 ) was a pioneering Soviet Russian film director and film theorist , often considered to be the `` Father of Montage . ''
Simplified: Sergei Mikhailovich Eisenstein ( ; January 23 , 1898 â `` February 11 , 1948 ) was a Soviet Russian film director and film theorist .