With characteristic British self-deprecation, Evelyn Waugh wrote that he didn’t believe that more than two Americans would enjoy his 1945 novel “Brideshead Revisited.” That notion was scotched when the book became a best seller and was rendered even more absurd by the wildly popular reception that greeted the 11-hour Granada television adaptation of “Brideshead,” which aired on PBS in 1982 — replete with eloquent introductions from the late William F. Buckley Jr.

Waugh’s saga, chronicling the declining fortunes of the aristocratic Catholic Flyte family, has now become a feature film, “Brideshead Revisited,” which opens next week. The television adaptation’s popularity was partly due to its striking fidelity to Waugh’s novel, but the movie takes more liberties with its source material. Just as its narrator, the atheist artist Charles Ryder, is consumed with nostalgia for Brideshead, the Flyte family’s ancestral home, many Waugh devotees watching it might find themselves nostalgic for the Granada TV series.

While the historic Yorkshire house Castle Howard doubles as the namesake estate in both the small-screen and movie versions, it is doubtful whether the film can match the societal and stylistic impact of the TV drama. Coinciding with Britain’s “Sloane Ranger” movement that promoted poshness in dress and style, “Brideshead Revisited” extolled the virtues of the three-piece suit and cricket sweaters. “‘Brideshead’ was used as a style catalogue,” a British writer who helped popularize the term “Sloane Ranger,” Peter York, wrote in his book “Eighties.” Meanwhile left-wing commentators objected to what they considered the elitist subject matter of “Bridehead,” linking it to the renewal of the Conservative Party under the then-prime minister, Margaret Thatcher.

A technicians’ strike brought filming of the TV adaptation to a halt in 1979; upon resumption, Sir John Mortimer’s script was abandoned, with the revised version far more faithful to the book. Actor Jeremy Irons, as Charles, got to deliver more of his haunting voice-over and there was longer screen time for British acting greats Lord Olivier and Sir John Gielgud.

“It’s a bit of a challenge to do justice to the book in a two-hour movie,” the new film’s co-writer, Andrew Davies, said in an interview. The film is directed by Julian Jarrold, who made last year’s Jane Austen biopic “Becoming Jane.” “Brideshead Revisited” stars Matthew Goode as Charles, and Ben Whishaw and Hayley Atwell as the siblings Sebastian and Julia Flyte. Michael Gambon and Emma Thompson play Lord and Lady Marchmain, the separated couple whose son Sebastian ends up an alcoholic in Morocco and whose daughter Julia embarks on a doomed relationship with Charles following a failed marriage to a Canadian politician.

The new “Brideshead Revisited” had a turbulent production history. Speaking on condition of anonymity, a source on the film said that in addition to real-life husband and wife Paul Bettany and Jennifer Connelly being originally cast as Charles and Julia, Kristin Scott Thomas was to have played Lady Marchmain. When original director David Yates left to make “Harry Potter and the Order of the Phoenix,” the game changed.

Mr. Davies had his screenplay extensively rewritten by the film’s other co-writer, Jeremy Brock. Mr. Davies said his version focused more on the love story between Charles and Julia than on the relationship between Charles and his Oxford University contemporary Sebastian, which dominated the TV series. Waugh wrote “Brideshead” to illustrate the grace of God set against the complexities of human relationships and the hold Catholicism can still exert on those whose faith has lapsed. But Mr. Davies said he envisaged making a tragic film that shows the unfavorable impact of religion on many people’s lives — “as much as the period when the book was written, although perhaps in different ways.”

Mr. Davies’s intentions provoked uproar among “Brideshead” devotees who were particularly upset that Sebastian’s beloved teddy bear, Aloysius, was to be excised from the film. Mr. Mortimer, in a radio interview, said: “If you were to take out the teddy bear it would be an outrage to Evelyn Waugh.” In the final cut, Aloysius now has what Mr. Davies calls a “cameo appearance.” The reinstatement of the teddy bear encapsulates the fact that, like the Granada series, the film ended up closer to Waugh’s book than had originally been intended. But enough changes have been made to upset some purists.

In the book there are overtones that the relationship between Sebastian and Charles is homosexual, but the issue is ambiguous. In the film, Charles kisses Sebastian only for his advances to be rebuffed. Or as Mr. Jarrold told the Advocate magazine: “We’re much more clear from the very beginning that Sebastian is gay.” The love triangle aspect has been intensified with Sebastian expressing resentment at Charles for wooing his sister (the book compartmentalizes the two relationships). The Oxford scenes have been reduced.

Waugh is considered to be one of 20th-century literature’s supreme masters of dialogue, but the film has excised many of his lines from his novel. “In my version, I used as much of Waugh’s dialogue as I could,” Mr. Davies said. “In the finished version, there is a lot of rewritten dialogue. I felt, if it ain’t broke, why fix it?”

Perhaps anticipating a rough ride from the British press, who savaged Stephen Fry’s 2003 Waugh adaptation, “Bright Young Things,” “Brideshead Revisited” is opening first in America in the hopes that buzz will cross the pond.

But Evelyn Waugh’s grandson Alexander Waugh, whose acclaimed family memoir “Fathers and Sons” was published last year, declared himself satisfied. “It’s a powerful film,” he said. “I would have liked more humor in the mix and the pace could have been faster but the film is not supposed to be the book.”