Producer, director and editor Chun-Wei Yi joins us to discuss his film “Rare: Creatures of the Photo Ark,” a new three-part PBS series premiering on July 18. Yi will be joined by the film's subject: author, conservationist and National Geographic Fellow Joel Sartore. The film follows Sartore as he works to complete the Photo Ark, a project he started with the goal of photographing some of the rarest, most vulnerable creatures on earth. Sartore's images have been projected onto major landmarks including the Empire State Building, the Taj Mahal, and in Times Square in order to raise awareness about the fragile condition of these rare species. The first episode of "Rare: Creatures of the Photo Ark" airs on July 18 at 9 p.m. on PBS. The next two episodes air July 25 at 9 p.m. and on Aug. 1 at 9 p.m. A photo of a monk saki from Joel Sartore's Photo Ark. (Joel Sartore)   A photo of a great Indian civet from Joel Sartore's Photo Ark. (Joel Sartore)