In 1982 he joined Simon Hartog and Keith Griffiths to form Large Door, the company that bid successfully to make Visions, a magazine series on world cinema for Channel 4 when it opened in 1982. Visions ran for three series until 1985. Griffiths left the company in 1984, but Ellis and Hartog continued producing documentaries separately and together until Hartog's death in 1992. Large Door made over 100 documentaries until it ceased production in 1999. The company produced two documentaries on the Cinema of China presented by Tony Rayns: Cinema in China outlined the history, hitherto scarcely known in the West; and New Chinese Cinema concentrated on the 'Fifth Generation.' Large Door also produced:
His work concentrates on television and related media. In 1982, he developed a medium theory approach, proposing that television's typical regime of spectatorship is that of the 'glance' rather than the more cinematic one of the 'gaze', and exploring the segmented and repetitive structure of TV programming. In Seeing Things he proposed the periodisation of television history into the three eras of 'scarcity', 'availability' and 'plenty', and applied the psychoanalytic concept of working through to television in the latter two eras. He also examined the crucial role played by scheduling in the organisation of creativity in TV and of the TV experience. Recently he has developed the concept of witness in relation to audio-visual material in a debate with, among others, John Durham Peters and Paul Frosh. This work is extended in his Documentary: Witness and Self-Revelation which applies an interactionist approach derived from Erving Goffman to the understanding of documentary. He argues in addition that contemporary viewers, now thoroughly familiar with the processes of filming and being filmed, adopt a much more skeptical attitude to the 'factuality' of documentary and to the ethics of filmer-subject interaction. His work on television history includes several articles on Channel 4; on critical issues including the construction of a canon of TV work; the importance of overlooked items such as interstitials; and decade-long involvement in the EU funded archival projects Videoactive and EUScreen In 2013 he won a European Research Council grant of €1,600,000 for ADAPT a five-year study of the history of technology in TV broadcasting, concentrating particularly on the standard forms of production and the ways that these 'technological arrays' were adopted and brought into regular use.
"Interstitials: How the Bits in Between Define the Programmes" in Ephemeral Media, ed Paul Grainge 2011
"Mundane Witnessing" in Media Witnessing, ed Paul Frosh, Amit Pinchevski, 2008
"Is it Possible to Construct a Canon of Television Programmes? Immanent Reading versus Textual Historicism" in Re-Viewing Television Histories, ed Helen Wheatley 2007
"Visions, a Channel 4 Experiment 1982-5" in Experimental British Television, ed Laura Mulvey, Jamie Sexton, 2007
"Documentary and Truth on Television: The Crisis of 1999" in New Challenges in Documentary, ed J.Corner & A.Rosenthal 2005
"Television Production" in The Television Studies Reader, ed. R.Allen & A.Hill 2003