The GlobeDocs Film Festival, the five-day documentary film fest sponsored by the Boston Globe, opened Wednesday with a sold-out screening at the Coolidge Corner Theatre of “Bending the Arc,” director Kief Davidson’s film about Harvard med students Jim Kim and Paul Farmer — and clinic volunteer Ophelia Dahl — who became the vanguard of global health. (The film is executive produced by Matt Damon and Ben Affleck.) Farmer and Dahl both attended Wednesday’s screening, which was met with enthusiastic applause. GlobeDocs runs through Sunday in conjunction with HUBWeek. Pictured above are Pulitzer Prize-winning author Tracy Kidder (left) and Farmer. At right are producer Cori Shepherd Stern (left) and Dahl.