Which work counts as the first film?
The answer depends on a definition no historian owns. Louis Le Prince shot moving photographic sequences at Leeds in 1888, Edison's laboratory showed Kinetoscope films to individual viewers from 1893, the Skladanowsky brothers projected to a paying Berlin audience in November 1895, and the Lumiere screening of 28 December 1895 is the industry's conventional birthday. Each candidate satisfies a different definition of film: recorded motion, exhibited motion, projected motion, or a paying public audience, and the field has not settled which definition governs.
What would resolve this Nothing empirical; this is a definitional question. What would settle it is a discipline-wide convention on which criterion defines the medium, or the recovery of lost apparatus and footage, Le Prince's above all, that would strengthen one lineage's claim.
Film History, Archival ResearchDavid A. Cook, A History of Narrative Film