Exclusive | A real Catholic cardinal let Ralph Fiennes try on his robes for Conclave: Invited him to his chambers

Ralph Fiennes was hanging out with a Catholic cardinal.The “English Patient” actor was preparing for his next role, as Cardinal Thomas Lawrence in the pope movie “Conclave,” in theaters Oct.25, and wanted to spend time with the real deal.Head-first Fiennes went a bit further than that.“I get a text from Ralph, who had met a cardinal, and the cardinal had invited him to his chambers,” Oscar-winning director Edward Berger told The Post. “On the bed in his chamber was laid out the cardinal robe.

And then Ralph sent me a text of a photo of him… in those robes, in the real robes, with a beaming smile like this.So proud.”There was a problem, however, because Berger, who directed Best Picture nominee “All Quiet on the Western Front,” was going in a different direction with the official outfits.“The costume designer and I knew that we don’t love the way the present-day cardinal robes look,” he said.

“The red is a little bit orangey and the fabric is not as luscious as you might think.” But, as actors often do, Fiennes, 61, had instantly clicked with the garment. “I needed to call him and say, ‘It looks great, but that’s not what it is going to look like,” Berger recalled.“He said, ‘Look, that’s the real thing.’ And so it took a little bit to convince him to put on this one.”Clothes weren’t the half of it.

Berger and production designer Suzie Davies (“Saltburn”) went to extraordinary measures to recreate, embellish and occasionally invent the mysterious world of Vatican City and the papal conclave, the secretive process of picking a new pope.“They won’t tell you what happens behind closed doors in the conclave,” the director said of the tradition-bound church.“And there are certain things you have to take license with.”And as “Conclave,” which also stars Stanley Tucci, John Lithgow and Isabella Rossellini, is a scandal-packed thriller based on Robert Harris’ controversial 2016 novel, the Vatican d...