Though he made his acclaimed movie “Carol” from the late Patricia Highsmith’s novel “The Price of Salt,” Todd Haynes laughed when asked what kind of conversation he would have wanted to have with the author herself.

“First of all, I would have been scared s—less,” said Haynes, referring to Highsmith’s reputation for frequently being irascible. “But maybe talking to the young Patricia Highsmith might have been a bit easier.”

That said, Haynes turned reflective during a recent chat in Chicago and noted that his primary interest would have been to ask Highsmith about the “invisible lines she draws in between her characters in her novels. … In this case, it would be tying together two very different women falling in love, as happens between Therese and Carol. It’s so different from the characters with criminal minds in her other novels. I guess that’s what I would have liked to talk to her about — her process.”

The concept of “process” was central to Haynes’ approach in crafting “Carol.” An important aspect was trying to find a way to give universality to the romance between his two central characters.

“Yes, it was very much a time when this would have been a very forbidden love, but that’s not what I’m talking about,” said Haynes. “It’s about a young and unformed person — in this case Therese, played by Rooney Mara — who wears her heart on her sleeve and is falling for the older woman — Cate Blanchett’s Carol — who has all the power.

“To my mind that kind of relationship is something you can find at any point in history when you have two people falling in love, no matter their gender.”

Cate Blanchett in "Carol." | The Weinstein Co.

Cate Blanchett in “Carol.” | The Weinstein Co.

Haynes knows he was lucky to have two extremely gifted actresses with which to communicate a number of emotions in “Carol.” With Oscar winner Blanchett, the director said, “she achieved so much here. She conveyed the vulnerability of the character who on the one hand understood how she was seen through Therese’s eyes, and yet also, on the other hand, was living a very unhappy, frustrated life with her husband.

“Cate knew instinctively how to navigate that very delicate acting maneuver beautifully.”

As for Mara, Haynes added that like Blanchett “she was so aware of the entire mechanical — as well as artistic — approach of the actually filmmaking process. She knew every second where the camera was and what it was doing. To have both actresses so in tune with that process made my job a heck of a lot less stressful.”

To capture the look of “Carol,” Haynes said he initially set out screening movies from the early 1950s, but quickly was disappointed. “So many of the films from that time were not very helpful, because they didn’t mirror the tenor of the story I wanted.”

However, he stumbled upon a film that did help him a great deal — “Little Fugitive” from 1953, directed by Morris Engel, whose wife, Ruth Orkin, was frequently his professional partner as well and a talented photographer. “In watching that movie, plus their later ‘Lovers and Lollipops,’ I discovered a certain kind of woman who expressed a certain kind of femininity that doesn’t exist anymore, unless you see a glimpse of it in your grandmother. It’s they way they carry themselves. It’s an expression of great poise. It’s that certain way those women from that period moved and talked.

“It’s not like modern women, and so watching those films was very useful, not just to me, but also to Cate and Rooney as they created Carol and Therese.”

The film was shot in Cincinnati, and the city was used to re-create both New York and Chicago scenes, including a key sequence set at Chicago’s Drake Hotel in the early ’50s.

“Fortunately, my very talented production designer Judy Becker is from Chicago and recently had returned from visiting her father. I was staying at the old Hilton Hotel in Cincinnati, and Judy pointed out, ‘The exterior is a dead ringer for the Drake!’

Becker was such a stickler for details that she was able to re-create a wooden sign with a downward arrow — “directing people to go down the stairs to the Cape Cod Room, on the ground floor,” Haynes said.

“It’s the kind of detail one needs when you make a film like this.”