Andy Warhol piloting John Denver’s experimental bi-plane: Christopher Makos’s best photograph

In the summer of 1977, Andy Warhol and I took a trip to his house in Aspen, Colorado. He loved that part of the world, partly because he loved pretending he could ski, but also because a number of his greatest collectors were based around there, many of whom were friends, too.

On this occasion, we went to visit the singer John Denver, who had a bunch of airplanes, from small private jets to this experimental bi-plane. When I saw it, I told Andy to jump in. But those things are actually pretty small and difficult to enter – it’s not like you can just hop in. Andy couldn’t manage it, so I told him to stand on the other side of the cockpit instead, and angled the lens to make it look as though he was inside the thing.

It felt right shooting him in this strange old plane, because so much of our time together was spent travelling. It feels fitting, too, because even though Andy was a quintessentially American artist who never really looked to Europe for inspiration – from the Campbell’s soup cans to the Brillo pads, he was American to the core – his work is now so global, there’s almost nowhere in the world that his work hasn’t travelled.

His facial expression was a trademark in the photographs that he made public. It’s this perfect neutrality: I’m not happy, but I’m not unhappy either. There was always an ambiguity he wanted to convey – almost as if it was up to the viewer to decide what he was doing, how was feeling, which “Andy” he was being on that particular day.

He was the same in interviews. He would almost never go into detail. Answers were yes, no, or at most a few words here and there. He never wanted to let on what he actually thought. I think he sensed, before his time, the importance of never giving too much away, always keeping something back, out of the public gaze.

It’s funny because in private, he was just so different. He could talk about anything, all day long. He was a fantastic conversationalist, especially at a dinner party. There was a sophistication to the way he interacted with the world that I always admired. One thing I treasured about him was his naivety in the face of new things. He and I were the same in that respect: we were never too cool to be amazed by something. Maybe it was a new place, or new food – but he had an innocent enjoyment of new things that was always so pure.

I think we became close because we had so much in common, beyond just our love of art and photography. We were both Catholic boys. We went to similar schools. We shared the same values. And we both had the same work ethic: when we worked, we worked hard; and when we played, we played really hard.

Over the course of our friendship, I took more photos of him than I can count. There are a few where he had no idea he was being photographed: it was him without his “Andy” suit on if you like, but I don’t find them more interesting than the others. I like my subjects to know they’re being photographed, to pose a little, because it’s a form of interaction with the photographer that can kind of go anywhere. It’s so much more fascinating to me.

I’ve always loved portraiture, whether in a studio or out in the world. So many images are about the surface, but in a portrait, I want to get inside, to understand and express something deeper than an appearance.

The first 15 minutes of any portrait session is about waiting until the person reveals themself. I’m clicking the shutter, but I’m usually not taking pictures. I’m talking, asking questions, trying to understand who they are. Only then am I actually capturing that person: no matter what they’re wearing, whether it’s nothing or something really fabulous, it’s only then you truly get to see someone. When that person allows themselves to be vulnerable with you, you can get a great photograph.

People often ask me if I miss Andy. But there’s really no time to miss him, because I’m always involved with my photographs of him that I took, looking back at them, arranging them for exhibition, interacting with them and my memory of him.

Christopher Makos’s CV

Born: Lowell, Massachusetts.
Trained: Self-taught.
Influences: Man Ray, Andy Warhol, Paul Solberg.
High point: “Moving to New York City.”
Low point: “Leaving Los Angeles.”
Top tip: “Consistency.”

• Christopher Makos’s work is part of Andy Warhol’s Insiders, a group exhibition and shop takeover at the Gagosian Shop, London, until 8 July.