The threatening atom bomb casts a baleful shadow over the serious young people who inhabit “Guns of the Trees,” the first feature made by the hugely influential filmmaker and activist Jonas Mekas. Shot in and around New York in the early 1960s, the 75-minute, black-and-white movie projects a sense of beatnik doom as evocative as it is dated.

In notes distributed at the movie’s premiere, Mekas, who died last year at 96, called it his “meditation on love and death in a period of darkness,” and “Guns” is a period piece. That it is showing, at Anthology Film Archives in Manhattan through Jan. 29, in a 35-millimeter restoration print made from the original negative, burnishes its anachronistic quality.

When “Guns” opened commercially in February 1964, two-and-a-half years after its first screenings, The New York Times critic Eugene Archer cautiously noted that the movie “has been sparking controversies among observers of its genre at private screenings here and abroad” and called it “one of the farthest out of far-out films.”

Essentially, the movie concerns two couples. One pair Barbara and Gregory (Frances Stillman and the filmmaker’s brother Adolfas Mekas) is white and gloomy. The other Argus and Ben (named for their actors, Argus Spear Juillard and Ben Carruthers, a principal in John Cassavetes’s “Shadows”) is black and life-affirming.