Kimi was lucky enough to hear this interview, and she was good enough to send us a report:
“Last Friday morning (11 August) Kim Hill of Radio New Zealand interviewed Humphrey Carpenter, the biographer of J.R.R. Tolkien. The interview was on the subject of Humphrey Carpenter’s latest work, a biography of playwright Dennis Potter, but towards the end of the interview Ms Hill asked Carpenter what he thought Tolkien’s reaction would have been to “The Lord of the Rings” being filmed.
Carpenter’s response was interesting. He said that he had known JRRT fairly briefly (unlike Potter, whom he never met), and that he (Carpenter) had staged a production of “The Hobbit”. JRRT’s reaction to this production was that he considered his works to be unstageable; he simply didn’t feel that they could be successfully translated to a dramatic form. Although he had sold the film rights long before this took place, he had no real expectation that “The Lord of the Rings” could be successfully filmed.

Carpenter himself made the rather startling remark that he thinks that “The Lord of the Rings” is unfilmable. He certainly startled Kim Hill, who laughed and said as if reading a headline, “Humprey Carpenter says ‘Lord of the Rings’ unfilmable!”. He said that, while Volumes I and II are very good, he feels that Volume III is rather wordy and has language that is almost biblical. One got the impression that, while Humphrey Carpenter considers “The Lord of the Rings” a very good book, he doesn’t necessarily consider it one of the great works of the 20th century. This is, however, only my impression of a rather brief and “off-topic” portion of the interview. And he did say that he intends to go to the films.”
Thanks for that, Kimi!