Roger Ebert silently presides over these proceedings here at Cannes. He’s long gone from this physical world but his legacy steadfastly endures — especially this year, partly due to the documentary of his biography “Life Itself,” playing to rapturous reviews here at Cannes, and partly from the presence of Ebert’s wife Chaz, a vital force for film criticism here at Cannes, and online as she continues to run the website, RogerEbert.com. But he hovers for another reason. There were few enough major critics who could balance their love of cinema with their job as film critics when Ebert was still here to show us how. There are far fewer of them now. Ebert’s reviews puts films in context for people because through most of Ebert’s life people actually bought tickets to serious films. You’ll never run out of meeting people, film fans, who credit Ebert with both their love of movies and with their own ability to discern the best of them.