Cate Blanchett in "Carol"

It was one of the better phone calls Elizabeth Karlsen has received during her illustrious career, though not an unusual one. For years, the British producer, who with her partner Stephen Woolley has made films such as “The Crying Game,” “Little Voice” and “Made in Dagenham,” had commiserated with the legendary American indie producer Christine Vachon from across the pond about how their productions were going (“which we are pretty much [doing] everyday,” Karlsen says). Karlsen was grappling with a particularly frustrating experience on “Carol,” an adaptation of Patricia Highsmith’s tale of a clandestine romance “The Price of Salt,” when she gave her pal a ring. After already jumping through hoops just to get the book rights for screenwriter Phyllis Nagy, who first mentioned the novel to her while working together on the 2005 black comedy “Mrs. Harris,” Karlsen had lost a director to scheduling issues in 2011, the latest in a long line of setbacks, when Vachon mentioned that the film she was working on with Todd Haynes couldn’t secure the right actor.

“So Christine said, “Well, why don’t we send Carol to Todd?” Karlsen says, beaming from ear to ear while recounting this tale, sitting beside Vachon recently in Los Angeles. “We had this incredible moment on that phone call which led to the movie that you’ve just seen.”

The simplicity of the solution is fitting for a gem like “Carol,” which, besides the literally prismatic qualities of Ed Lachman’s shimmering cinematography, gleams as only something that experienced intense scrutiny beforehand. Every scene is immaculately crafted from the period detail to emotional precision of the performances Haynes elicits from Cate Blanchett and Rooney Mara. But long before any of them even got to set, the film was a 15-year effort that ushered Nagy into screenwriting after serving as a playwright for the Royal Court Theatre, drawing upon the friendship she struck up with Highsmith towards the end of her life, while Karlsen herself had traveled to Zurich to read the author’s diaries and letters while waiting out another producer that had the rights. While the film is in theaters, Karlsen and Vachon shared the details of a difficult road to production, as well as how things quickly fell into place once Haynes was onboard.

Rooney Mara and Cate Blanchett in "Carol"Was it interesting to approach Todd Haynes with something he didn’t originate himself?

Christine Vachon: Yes, although what gradually began to happen over the years is that he had been getting more scripts that he hadn’t written himself. “Mildred Pierce” was an adaptation that he collaborated on Jon Raymond, so I think when he read the script [for “Carol”], it really resonated with him right away and he worked with Phyllis — he has to inhale a script to make it his own. So there were some things that he brought to it, probably the most notable is the framing device that was obviously taken from “Brief Encounter.”

Elizabeth Karlsen: [laughs] Inspired rather.

Christine Vachon: Inspired by “Brief Encounter.” Some people say to me, “Are you aware that that framing device … ?” [laughs] And I’m like, “No, we have no idea.”

Elizabeth Karlsen: “No, we’ve never seen David Lean’s Brief Encounter.” One of the greatest love stories of all time.

Christine Vachon: That among other things he actually brought to the script.

Because a number of directors were attached at one time or another, was it an issue of scheduling or was it actually difficult to nail down a take on this that would work?

Elizabeth Karlsen: Even though I had wanted to make it for ten years before I finally got the rights, I don’t really know the details of what happened before I was on board. There were various directors, like Rose Troche, I think it went across her desk, and [Christine] said Kimberly Peirce …

Christine Vachon: Yeah, there was a producer out there who was trying to get it made.

Elizabeth Karlsen: But we don’t really know the details of that. Once I got it in 2010, we went through two directors that didn’t work for various reasons, [primarily] availability — and then once Todd came on board, it was very, very quick. Todd got the script in May 2011 and we were shooting in February 2012. He and Phyllis established such a good collaborative relationship so quickly, and once Todd was on board, Cate [Blanchett] said, “I’m in.” And obviously they’d worked together with Christine so successfully in “I’m Not There,” which is such an incredible movie — there was so many extraordinary things that seemed like they were meant to be for “Carol” that came together. There was a kind of snowball effect.

I’ve even heard it wasn’t even that hard to find a location since Elizabeth had worked on “A Rage in Harlem” so many years ago.

Elizabeth Karlsen: Yeah, because we made that film there over 25 years ago and used it for 1952 New York, but it never occurred to me that in 25 years it wouldn’t have undergone some great urban renewal. There was a preservation of the inner-city architecture, so there was just block upon block of these incredible buildings that were such a perfect match, it was like it had been preserved in aspic, much of it.

Christine and Todd had just come off of “Mildred Pierce,” but is doing a period piece much more difficult in general to construct?

Christine Vachon: Our expression with period is “you pay by the yard,” so when a director’s putting his or her hands out [open wide] like this to tell you what they want to see, you want to push their hands together. But one of the great things about Todd is, he’s very specific about what you’ll see in the frame. If he’s going to shoot in this room and it has to be dressed a certain way, he’ll be able to tell you far in advance that we’ll just see this portion of it, so we don’t have to worry about the rest of it, which is a very economical way to make the most of the money. He’s been asked about this a lot recently, because when you really think about it, he’s only shot period films in the past. “I’m Not There” jumped around between multiple periods, and he said he just loves the idea that if you’re making a period film, he has to put every single thing in the frame. Nothing can be there by chance.

Elizabeth Karlsen: I’ve known Todd for a long time, but I hadn’t worked with him before as a director, so Christine would call and [say] we couldn’t get the normal props guy — and there was a lot of pressure on making sure the props department was right [because] Todd just cannot shoot unless that lipstick that Carol puts on in that scene is exactly the right lipstick case. There’s such specificity that goes into what’s in the frame. But that is the extraordinary thing about Todd, and you see it so strongly in “Carol,” is that the period visual detail does not take precedence over the emotion that is generated from the narrative. Often in period films, it becomes all about the look and the rest of the story doesn’t resonate. In “Carol,” as well in all of Todd’s films, you really see that. It’s such a thing of absolute beauty. He pours his heart and soul into every frame of the movie, and yet it is an extraordinary and exhilarating love story.

Did it present challenges to finance as a gay love story?

Elizabeth Karlsen: It is because we raise the finance for our films kind of bit by bit and package the financing together, which really can mean selling territory by territory, so when you are presenting it, it is Cate Blanchett, and it’s one of the great directors of modern cinema in America. But people say he’s an art house director, it is a film with two women, those two women are gay, and it’s a period film, so it absolutely presented challenges for financing. We were very, very, restricted with what we had to work with, but Todd, along with his whole team, did an incredible job making that go a long way.

Christine Vachon: Female-driven films [in general] are always hard. Last year, we had “Still Alice,” and you can look how far that went, but that was also an impossible film to get made. We find ourselves always struggling with, if you’re interested in stories that are driven by female characters, there’s always a lot of pressure. There’s a ridiculous amount of pressure on who the secondary male characters are played by. Whereas if it was reversed it wouldn’t be at all. And that’s frustrating because from where we sit [because] those stories are just as viable in the marketplace.

Was there a particularly challenging day of shooting on “Carol”?

Christine Vachon: All of them.

Elizabeth Karlsen: There were only 35 of them. That was challenging. Maybe if we had 45 they would be less challenging.

Christine Vachon: We were trying to achieve so much within a very limited amount of time and with very limited resources.

Elizabeth Karlsen: The first day we had a hail storm and the camera truck almost blew into a pond. It was caught at the last second. Then we had brilliant sunshine [followed by] tornado-style rain. I was like, “I don’t think I’ve ever been in a city where this happens.” And a local said to me, “You know what they say? If you don’t like the weather come back in 15 minutes.” And I thought, “Okay, this is going to be easy.”

Christine Vachon: Luckily, there weren’t that many exteriors.

Elizabeth Karlsen: And the people of Cincinnati really rallied around this film and embraced it in a way that enabled us to do things that we wouldn’t have done elsewhere. Even the period cars, that we put out a call for, people came in droves. They got those vehicles that they had in their garage, neatly polished that they loved and cared for, and they were on the set of “Carol.” It was great, and the extras were incredible.

What’s it like to bring into the world now?

Christine Vachon: It’s great, but every time you make a movie, you set out to make a fantastic movie. You just never know if you’re going to be able to thread that needle where it meets your expectations or exceeds them, then if the critics agree, and they like it, and then the public actually wants to go see it. If you can line all that up, it’s just an amazing feeling.

“Carol” is now in theaters.