CANNES—The creative process involves a delicate balancing act between listening to and absorbing the opinions of others and staying true to yourself, Peruvian fashion and portrait photographer Mario Testino told an audience in Cannes.

Speaking at a session on “The Magic of Mario,” introduced by Jackie Cooper, global chair of creative strategy at Edelman, in conversation with Elaine Welteroth, editor-in-chief of Teen Vogue, Testino talked about the insecurity he felt in his early years, as an outsider who initially sought to emulate others, before he realized the importance of being true to himself.

“I was afraid of my weaknesses,” he told Welteroth. “I was able to negotiate that I would only give my clients one picture that was the picture. My mistake at the beginning was that I would underestimate the value of other opinions. At the end of the day, I am the boss and I will decide, but it’s important to listen to other opinions.”

The key, he said, is to “work with people you respect, people who push you. I am not always right; I did make a mistake in 1972,” he joked. “Listen to advice, digest it, take what you need and discard the rest.”

So he listens, particularly to clients. “Most photographers want the image to be their image, but I realized that by entering other people’s worlds and applying my know-how, I could give them their own image. The image is not about me, it’s about them.”

At the same time, he stressed the importance of being true to his own vision, discussing the pushback he got when he first worked with models like Cara Delevingne or Gisele Bündchen. “Somewhere along the line I have to follow my gut. Sometimes you have to convince people” of the need to take risks. “It’s important to believe in yourself. You have to be secure in what you say and fight the insecurities of other people.”

Discussing his creative process, he said: “I see no difference between advertising and editorial, because at the end of the day you are working with a brand. Vogue is a brand, and you have to be true to the brand.

“I listen to a lot of conversations. It’s very important, discussion, listening. And then I do a lot of research. But most important is I follow my gut, I don’t like offering the client ‘you can go this way or this way or this way,’ because for me there is only one way.”