YOU’VE never seen a film noir quite like 1947’s freaky “Lady in the Lake,” which finally arrives on DVD Tuesday as part of the “Film Noir Classic Collection, Vol.

3″ (Warner, $50).

Robert Montgomery stars in this undeservedly obscure gem as Raymond Chandler’s hardboiled detective Philip Marlowe – the same sleuth played by Humphrey Bogart in 1945’s “The Big Sleep” and Dick Powell in 1944’s “Murder, My Sweet.” But Montgomery, a popular star who also made an auspicious directing debut with this film, is only seen as Marlowe delivering narration to the audience at the beginning and end of the movie – and in a few shots where Marlowe looks in a mirror.

“Lady in the Lake” is the only mainstream Hollywood movie filmed almost entirely with a subjective camera, often with striking results.

“YOU accept an invitation to a blonde’s apartment,” MGM’s ads promised. “YOU get socked in the jaw by a murder suspect!” As Marlowe tells the audience, “You’ll see it as I saw it. You’ll meet the people. You’ll find the clues. And maybe you’ll solve it quick and maybe you won’t.” While not as labyrinthine as “The Big Sleep,” this is one twisty mystery. It opens one Christmas Eve, when Marlowe, who has been trying to sell his own detective stories, is summoned to a publisher’s office.

A cool brunette with dubious motives (the wonderful Audrey Totter) instead hires Marlowe to track down the missing wife of her boss (Leon Ames).

Marlowe’s search involves a dirty cop (Lloyd Nolan), a gigolo (Dick Simmons) and a mysterious landlady (Jayne Meadows) at the titular lake. And lots of punches hurled at the camera.

In one stunning sequence, Marlowe crawls out of a crashed car on his hands and knees as a Christmas choir plays on the soundtrack.

The other characters directly address the camera standing in for Marlowe.

“We had to do a lot of rehearsing,” recalled Montgomery, father of “Bewitched” star Elizabeth Montgomery and a onetime TV advisor to President Eisenhower. “Actors are trained not to look at the camera. I had a basket installed under the camera so that, at least, the actors could respond to me, even if they couldn’t look directly at me.” Though Newsweek called the movie “a brilliant tour de force,” audiences were cool to the “I am a camera” gimmick – which has been employed on a very limited basis ever since.