However lightly-regarded it might be in the canon of the filmmaker who gave us “The Red Shoes,” “Black Narcissus” and “The 49th Parallel,” Michael Powell’s “Age of Consent” seems something of a landmark,now. It’s a movie that had a reputation in its time, and that impacted the reputations of many of those involved with it, directly or indirectly.

Powell’s lush Technicolor pictures of the ’40s and ’50s kept their sex mainly in the realm of sublimated psychology. But “Consent” and his most scandalous film, “Peeping Tom” (1960) were movies that coated his career with a more lurid brush, in reflection.

Long before I started reviewing films with Helen Mirrren in them, she had a reputation for daring nudity on the screen, something chiseled in stone, willingly or exploitatively, with this her breakout feature. “Excalibur,” “The Cook, the Thief, His Wife and Her Lover” — by the time “Calendar Girls” rolled around, she was ready to mock that rep.

And if you never made the connection between the Irish-born, Kiwi/Aussie actor actor Sam Neill and James Mason, this film makes it stunningly obvious. Mason plays the lead, a character the Australian painter and novelist Norman Lindsay based on himself, an artist who loved being surrounded by gorgeous models. Neill gave us his version of Lindsay in “Sirens,” his first Oz film after his “Jurassic Park” breakout.

The accents are different, with the non-Irish Mason more posh and patrician by nature. But the timing, intonations and understated “animation” of eyebrow expression are damned near uncanny. I wouldn’t be surprised in Neill saw this film as a lad and got into acting because of this Down Under story.

No doubt the sight of Helen Mirren skinny-dipping would drive a lot of lads into acting.

The story’s not quite as creepy as the titles suggests. Not. Quite. But it wouldn’t be set up and cast this way today.

Mason plays Bradley Morahan, a famous Aussie abstract artist who has experienced about as much of New York as he can stand. He flies home, and is immediately hooked up with a former lover (Clarissa Kaye-Mason, who married Mason after they met on the set) and hunted down by a mooch of a former mate, Nat, played by veteran character actor Jack MacGowran (“The Quiet Man”).

Luckily for “Brad,” he’s set for a little enforced isolation. He’s headed for Checkabaronie, an island so far from everything “it’s a morgue, a dump, a desert island” Nat insists. And it’s off season.

Brad moves into a shack there, with a dog he’s named Godfrey, after his last New York art dealer. He starts decorating the place with dabs of color and found objects.

But he’s being watched, and robbed. Godfrey spied her first, hiding under the dock, stealing Morahan’s eggs. Cora (Mirren) is local, primitive and untamed, and below “the age of consent” her hateful drunk of a granny (Neva Carr-Glynn) reminds her.

Morahan starts buying her fresh catch — “crayfish” (lobsters) — and other seafood (and chicken) she can provide. And the greying, bearded painter takes a fatherly interest in her efforts to escape from her miserly grandmother and the isolation of this island.

He talks her into modeling for him.

Mirren, credited here as a member of “The R.S.C., The Royal Shakespeare Company,” is at her most playful in this film, striking coquettish poses such as Cora might have seen in magazines the tourists leave behind.

As Morahan is paying Cora to model, money which she can add to “escape from this island” kitty, she can reluctantly be talked into posing nude. But soon she figures out his regard for is strictly professional and starts to take on that air herself. Not that she likes that.

Mirren brings a youthful confusion to the performance of this arrangement, a girl bruised by her grandmother’s greed and drunken “You little slut!” labels. Cora’s late mother went wrong at about her age, turning into “the town bicycle,” who might give “anybody” “a ride.”

Mason, having a go at the accent and the Oz slang, embodies something Neill’s later mirrored in his interpretation of the painter who was writing a fictional account of his own life in this novel, Lindsay’s casual regard for female nudity. Mason’s Morahan has plainly has compartmentalized his interactions with this girl and doesn’t need the leering threats from her grandmother to behave like a detached adult when dealing with her, taking care to respect her privacy and even her reputation when his piggish pal Nat tracks him down again.

When the (somewhat) more age appropriate local fisherman/ferryman Ted (Harold Hopkins) tries to figure out the nature of their relationship, Morahan’s mind is anywhere but in the gutter.

“She’s all right, you know,” the young man chirps. “Glad to hear it” the older man distractedly agrees.

Powell put a lot of things on film he wasn’t known for in “Age of Consent,” from sex and nudity to underwater scenes and lots of genuine, Great Barrier Reef island (Dunk Island) local color. There’s virtually nothing here that smacks of “soundstage,” although the New York scenes had to be faked, and there are interiors that were most certainly sets.

I was surprised that the only real offense to modern sensibilities is fairly tame and confined to the faintly-icky finale. That can be read as a teen girl’s first serious “daddy issues” crush, or more transactional, “This is the geezer that can take me places.”

In any event, its sense of inappropriateness is more of a modern thing that would have merited no more than a raised eyebrow at any earlier point in history, from Jane Austen’s England to the “Swinging ’60s” in New York, London or Brisbane.

The film itself can be seen as the fine, lightweight curtain call it was, even though Powell made a couple of TV films before fully retiring by 1980. The story has a text and a lively sub text — everybody seems to be stealing from the artist, and he in turn, is stealing Cora’s ephemeral youth and immortalizing it on canvas.

It isn’t “The Red Shoes,” but even the great Michael Powell could only manage one or two those.

Rating: R, nudity

Cast: James Mason, Helen Mirren, Neva Carr-Glynn and Jack MacGowran.

Credits: Directed by Michael Powell, scripted by Peter Yeldam, based on the novel by Norman Lindsay. A Columbia release on Tubi, Amazon, etc.

Running time: 1:40