Celluloid depicts the life and times of J. C. Daniel, his pioneering love for Malayalam cinema. Rosamma, rechristened later as Rosie, essays the lead role in J. C. Daniel's revolutionary 'motion picture' venture, "Vigathakumaran". Chelangatt Gopalakrishnan's interest in Daniel's life, his efforts to give him his due and the flashbacks to the incidents in Daniel's life form the rest of the story.
