David Breashears, a mountain climber and cinematographer who reached the 29,032-foot summit of Mount Everest five times, including for a 1998 film that became the highest-grossing IMAX documentary ever, died on March 14 at his home in Marblehead, Mass. He was 68.

A representative of his family confirmed the death but said the cause had not been determined.

Among the tightly knit global community of high-altitude mountaineers, Mr. Breashears was known for his willingness to take enormous risks, balanced by an exacting attention to detail that made such adventures possible.

After years building his reputation as a climber in the American West, he began traveling to Nepal and the Himalayas in the early 1980s. After several aborted attempts, he reached the summit of Everest in 1983.

By then he had developed a second career as a cinematographer, working with alpine-related feature films and documentaries, and on this expedition he broadcast the first-ever live footage from the top of the world’s highest mountain.

His most famous ascent came in 1996. Sponsored in part by the Museum of Science in Boston, he and his team lugged a specially built IMAX camera, plus rolls and rolls of film, up the mountain.