Richard Gere may be best known for his work in front of a camera, but the American Gigolo and Pretty Woman actor has spent years collecting images from artists like Richard Avedon, Diane Arbus, Irving Penn, Manuel Álvarez Bravo, Edward Weston, and Herb Ritts. Now, more than 150 photos from the Richard Gere image collection are up for auction at Christie’s through April 7.

Gere told the Hollywood Reporter that he doesn’t see himself as a collector, but that his interest in images and the stories that they tell was sparked as a child. “That’s kind of been baked into me, an interest in images, whether it’s a dream-like suggested moment to one that’s definitive,” the actor said in the interview with Hollywood Reporter. “The process of film is really interesting. There’s nothing really there. It’s just grain or in the current process it’s just ink that’s shot onto paper, but there’s nothing really there. It’s just suggestions and the mind creates images and stories. The brain creates the images.”

[Read: ‘Black Women Photographers’ Grant Awards $50,000 to 12 recipients]

The Gere image collection, which is estimated to be worth at least $2 million, spans mediums from gelatin silver to albumen prints. With both historic figures like Gustave Le Gray and modern innovators like Sally Mann, the images span a wide range of historic artists.

While Gere says that he’s been interested in photography since first picking up a Kodak Brownie as a child, his collection started with his friendship with photographer Herb Ritts. The actor said that he started going to photo auctions with Ritts in his mid-to-late 20s, where the actor says he bought what he liked.

Roughly 50 years after beginning his collection, Gere says he doesn’t see himself as a collector. But, as an actor, he says he is drawn to images with story and emotion. “Being an actor, my basic tool is emotions. So I think most of the pictures that I respond to have the suggestion of a story or a flicker of the mystery,” he said.

[Read: Iconic Man Ray Image Has Record-Breaking Reserve Pice of $5 Million]

“These photographs arrived in my life because I felt something for them. They have real soul, a humanity, a generosity—it doesn’t matter what the technique is,” the actor added.

The Richard Gere image collection is being auctioned as more than 150 individual pieces. The Christie’s auction is online only, running through April 7.