Thirty years after her death, Alma Reville is still overshadowed by her husband.

That’s not just a crack about Alfred Hitchcock’s famously round profile, either. Reville was married to “Hitch” for more than five decades and was his screenwriter, editor and all-around creative partner, something he acknowledged and appreciated openly. Yet, when the spotlight finally shines on her in Sacha Gervasi’s “Hitchcock” — in the form of Helen Mirren, no less — she can’t even get her name in the title.

She’s the best thing about the movie, too.

The film portrays the ostensible main character (Anthony Hopkins, under distracting prosthetics) as an aging auteur looking for a new way to give audiences a jolt. He finds it in “Psycho,” a risky project that he has to finance himself, and that the usually on-the-nose Alma finds distasteful.

While he juggles on-set difficulties, she takes a side job with writer Whitfield Cook (Danny Huston), leading to speculation about her fidelity, both personal and professional.

When Gervasi focuses on the way Hitchcock made his masterpiece, he offers an entertaining look at how Hollywood was changing in 1959, and how one director shook things up when some people thought he was past his prime.

Gervasi and screenwriter John J. McLaughlin (adapting Stephen Rebello’s “Alfred Hitchcock and the Making of Psycho”) cast the supporting roles convincingly, providing Scarlett Johansson (as “Psycho” star Janet Leigh) and Jessica Biel (as co-star Vera Miles) with the best material they’ve had in a while.

And James D’Arcy (“Cloud Atlas”) absolutely nails Anthony Perkins’ shy, nervous insecurity. People in the screening audience actually gasped when he appeared, so if anyone ever makes a Perkins biopic, this is the guy to call.

Hopkins doesn’t look or sound much like Hitch, so you never forget whom you’re really watching, but he does convey his subject’s perverse, borderline sadistic sense of humor. He hints at other perversions, too, as references are made to a voyeuristic obsession with blond actresses.

Unlike the recent HBO movie “The Girl,” which makes Hitchcock a more sinister character, this film treats his behavior as a harmless middle-aged indulgence. It makes him more likable but a lot less interesting.

The decision to have him hold imaginary conversations with Ed Gein, the real serial killer who inspired “Psycho,” is similarly misguided, playing more like a sick variation on “Harvey” than anything else.

Alma pushes through all this to emerge as the strongest figure in the story, by far. She’s intelligent, patient and talented, and although the domestic drama is poorly written, Mirren’s performance brings depth to the soapiest moments.

“Hitchcock” may be a muddled and shallow portrait of its actual title character, but it shines a much-deserved spotlight on the great woman behind this particular great man.

(At the Glenwood Arts, Palace and Studio 30.)

MAKING A KILLING

While “Hitchcock” goes behind the scenes of “Psycho,” we open the curtain on that 1960 film’s most infamous segment: the shower.

• Filming took seven days — a third of the total time Janet Leigh was on set.

• A prop man provided the murder sounds by knifing casaba melons.

• Speaking of ruthless slicing, in an interview on “The Dick Cavett Show,” Alfred Hitchcock said, “Everything was so rapid that there were 78 separate pieces of film in 45 seconds.”

• The blood swirling down the drain is actually chocolate syrup.

• Hitchcock envisioned no music for the scene, but Bernard Hermann went ahead and wrote his iconic “Screaming Violins” score for it. Hitchcock then doubled the composer’s salary.

• After watching herself in the scene, Leigh reportedly gave up showers for the rest of her life and took only baths.

ADORING ALMA

Alfred Hitchcock often said publically how indebted he was to his wife, Alma Reville. For example, when accepting an American Film Institute Life Achievement Award, he said:

“Had the beautiful Miss Reville not accepted a lifetime contract, without options, as ‘Mrs. Alfred Hitchcock’ some 53 years ago, Mr. Alfred Hitchcock might be in this room tonight … not at this table, but as one of the slower waiters on the floor.”

WHAT OTHERS ARE SAYING

•  David Germain, The Associated Press: “Its spirit of whimsy (is) a wink that the filmmakers know they’re riffing on Hitchcock’s merrily macabre persona and not examining the man with any great depth or insight.”

•  Ann Hornaday, the Washington Post: “There’s something tonally off about the master of anxiety, neurosis and disquiet being depicted in a story this cozy.”

•  Kenneth Turan, Los Angeles Times: “Its protagonists turn out to be not especially interesting and the audience is not presented any convincing reason to care about what happens in their lives.”