The final Harry Potter film to feature Richard Harris as Hogwarts Headmaster Professor Albus Dumbledore. Harris died of Hodgkin's disease a few weeks before this movie's American release. Both Chamber of Secrets and its sequel Harry Potter y el Prisionero de Azkaban (2004) are dedicated to his memory.
Daniel Radcliffe was initially only offered £125,000 (approximately $181,500) for this movie. The actors' union Equity stepped in and negotiated new terms, which increased his salary to roughly £2 million ($3 million).
Executive producer and director Chris Columbus instructed cinematographer Roger Pratt to bring a darker look to the movie, reflecting the darker tone of the story. Hence, the sets were lit with more subdued lighting, and the color palette was desaturated a bit. These changes would continue throughout the franchise, with each movie getting darker and increasingly desaturated.
During production, Emma Watson frequently brought her pet hamster Millie on set. Unfortunately, Millie passed away shortly after shooting began. The set department created a specially-made hamster coffin, complete with velvet lining, and the name "Millie" engraved on the top. "I don't think a hamster has ever had a better send-off", Watson said.
During post-production, producer David Heyman went to visit Richard Harris in the hospital. Though he was very weak from his illness, Harris insisted that the role of Dumbledore not be re-cast. Sadly, Harris died shortly before production was to begin on the next movie, necessitating a re-cast.