There are a few ways to wrap your head around watching a seven-and-a-half-hour movie . When I was a kid I used to mark time in “Roseannes,” where 30 minutes would equal one Roseanne —the run time of the sitcom. My junior hockey games were two Roseannes. The drive to my uncle’s was 12. A seven-and-a-half-hour movie is 15 Roseannes, or a flight from New York City to Paris in an economy seat with no headrest. It’s a long time to sit and watch a movie, or do anything, these days. But that didn’t stop 250-plus people from doing it on a recent early-spring Saturday in Manhattan. Sátántango , Hungarian filmmaker Béla Tarr’s 1994 miserabilist epic about a failed Hungarian farming collective, clocks in at 439 minutes. The centerpiece of Film at Lincoln Center’s Farewell to Béla Tarr program this week (the director died in January, age 70), the film is something of a holy rite for hardcore cinephiles. It is rarely screened, and rarely seen.…