By Oscar Holland, CNN(CNN) — In Morris Lum’s photographic archive of Chinatowns, change is the only constant. In a video interview from his home in Toronto, Lum said he “really just wanted to keep a record” of Chinatowns. It was emotional, too: “My parents really craved that sense of familiarity that wasn’t really present in suburbs,” Lum recalled. The photographer experiences a similar sense of comfort when entering Chinatowns for the first time — even in cities he’s never visited before. It is in these interactions that he, ultimately, finds optimism about the future of North America’s Chinatowns.