The Newburyport Documentary Film Festival returns for its 21st year this Sept. 26 through 28. The festival brings to Newburyport the best in new thought-provoking and educational documentaries for a weekend each September. Many of the screenings are followed by discussions with the filmmakers and other experts. The festival also features films given the YES (Young Emerging Filmmakers Showcase) Award. A detailed schedule will be posted on the fest’s website in the weeks leading up the festival.