Stephen Shore began photographing Andy Warhol’s Factory in 1965, when he was just 17. Over 50 years on, his photographs still fascinate, offering an insight into one of the most compelling and important artistic moments of the 20th century.

The book, which is published by Phaidon, features images of all the main players at the Factory – Edie Sedgwick, Nico, The Velvet Underground, Billy Name etc – alongside other, less expected figures. Marcel Duchamp, Yoko Ono, Mama Cass and Allen Ginsberg all pop by, giving a sense of the immense draw of Warhol at the time. There are behind-the-scenes shots of art and films being created but perhaps some of the most appealing shots are the candid images, showing everyone just hanging out, always looking immensely cool.

Alongside the photographs are texts from many of the significant figures, reflecting on the period. Shore himself explains how he first met Warhol at a filmmakers’ coop, drawn together by a mutual interest in experimental film. “I asked him if I could come and photograph at the Factory,” he recalls. “He said, ‘Well, we’re going to Paris tomorrow, but we’ll call you when we get back.’ He was perfectly friendly, but there was a dreamy vagueness in his manner, and I didn’t know if I’d ever get a call. Then, really a month later, I did. It was Andy saying, ‘We’re filming at a restaurant called L’Avventura; do you want to come down and take pictures?'”

From his standpoint as photographer, Shore was given a window into Warhol’s working practise. “Andy came across as very insecure and would ask people what they thought of what he was doing,” he writes. “Although one always had a sense he knew just what he was doing…. My guess is that it helped him in his work to have people around, to have these other activities around him. I think he kept people involved by asking, ‘What do you think of this? Oh, I don’t know what colour to use. What colour should I use?’ Just something to keep the swirl of activity around him.”

And alongside learning about Warhol, Shore found he also learned how to be an artist himself. “I’d been doing photography for a long time by that point, but I had always done it in an untutored way. For reasons of my youth, and reasons of the lack of intensity of critical discourse around photography at that time, I think I was still very naive. I saw Andy making aesthetic decisions; it wasn’t anything he ever said to me. I saw these decisions happening over and over again. It awakened my sense of aesthetic thought.

“By the end of my stay at the Factory, I found that just my contact with, and observation of, Andy led me to think differently about my function as an artist.”

Factory: Andy Warhol by Stephen Shore is published this week, priced £39.95; phaidon.com