70mm showings of Christopher Nolan’s Dunkirk have proven to be very popular at the Irish Film Institute, just one factor in making the historical epic a major hit at the Irish box office. As part of the IFI’s commitment to exhibit, preserve and educate, they’re no strangers to showing films in a variety of formats, with authentic prints of films like The Right Stuff being regular features of IFI programming. The most recently announced example is upcoming screenings of a new 70mm print of David Lean’s classic Lawrence of Arabia, which will be showing at the cinema from Oct 20 – 22. But what exactly is the difference between 70mm and the more modern digital? How do great films go from the booth behind you to the screen in front of you? It’s hardly just a matter of pushing play on a DVD, as the IFI’s projectionist Paul Markey explains. Film In Dublin spoke to Paul about the work that he does, different film formats and more.