Eastwood, who at 84 just released the musical "Jersey Boys" and wrapped shooting on the Navy SEAL drama "American Sniper," isn't the only filmmaker blowing past conventional retirement age. [...] in May, 83-year-old Jean-Luc Godard, the perpetual enfant terrible, premiered his 3-D "Goodbye to Language" at the Cannes Film Festival. Polanski's film is a gloriously comic, self-referential gender play. At a time when literary giants like Philip Roth, 81, and Alice Munro, 83, have quit their craft, many of cinema's auteurs have stubbornly persisted, while at the same time churning out frequently acclaimed, often vibrant films in a youth-driven industry. [...] film history is littered with directors who worked well past retirement age. [...] longevity would only be possible for widely admired filmmakers who still have the drive to tell a story and the industry weight to attract financing. Because of tight-fisted studios, it's arguably harder today to get a movie made than ever before, adding to what's already a hugely taxing profession that demands tremendous energy and attentiveness through years of pre-production, shooting, editing and promotion. Martin Scorsese, 71, sounded slightly dejected by this part of contemporary moviemaking when releasing "The Wolf of Wall Street," an explicit romp of a movie few would associate with a director in his 70s.