As a cinematographer, Kai has shot numerous features in Hong Kong and other parts of the world. These include Berlin Teddy-Award winner All Shall Be Well; The Way We Talk; Pavane for an Infant; The Sunny Side of the Street; Drifting; Krabi, 2562; Suk Suk; Old Stone; Ek Hazarachi Note; Murmur of the Hearts; By the Time It Gets Dark; Mundane History; and Anson Mak's documentary On the Edge of a Floating City, We Sing. Festivals including Berlin, Locarno, Rotterdam, and New Directors/New Films have selected features he shot. Kai has been nominated for national awards for Best Cinematography in Thailand, Canada, and at the Taipei Golden Horse Awards, and at festivals in Malaysia, India, and the Philippines.

As a director, Kai's short film "Three Boys" represented the Philippines in competition at Clermont-Ferrand Short Film Festival and won the top-prize Gold Award at the Hong Kong Independent Film & Video Awards. It also screened at Sao Paulo, Austin, and Jecheon. "Lock" was in competition at the Tribeca Film Festival. Memories to Choke On, Drinks to Wash Them Down was his feature debut as co-director and co-writer. Memories premiered internationally at Rotterdam and received the Best Screenplay award from the Hong Kong Film Critics Society.