Kate Middleton

Legendary photographer Mario Testino has high praises for the many celebrities he's shot over his 30-year career -- including Prince William and Kate Middleton!

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In a new interview with The Telegraph published Saturday, Jan. 18, Testino, 59, shared his observations of the parents to nearly 6-month-old baby Prince George during their engagement shoot back in November 2010: "You could see they were completely in love," he said. "I waited a long time, an hour or two, to make that picture perfect," he said of their engagement session in the Council Chamber linked to Clarence House (where Prince Charles resides). "But I wasn't totally satisfied."

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"Then, when I'd finished the shoot, they were about to leave and they suddenly hugged in front of a radiator," he recalled. "I took my camera and that was the picture that ran everywhere -- it was spontaneous emotion ... you could see they were completely in love," he mused.

"Kate, she is beautiful in a different way," he said of her differences from the late Princess Diana, whom he famously shot in 1997 for Vanity Fair. "She radiates happiness. She is comfortable in her love," he shared of the Duchess of Cambridge, 32, who celebrated her birthday last week.

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The Peruvian-born photographer, who's revered for his portraits of Prince Harry, William and Diana, also shared his observations about the royal family members from previous shoots. Harry, 29, was "so like Prince Charles: they act alike, they have the same sense of humor, the same confidence." Testino observed that older brother William, 31, however, was "more like his mother, there's a kindness and a gentleness there that instantly wins you over."

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On their famous mum Diana, the photographer shared, "It was like a fairy tale. Who was she really? Why did she do this? She was trying to find love. I wanted the world to see her kindness, her humility: I think she realized that would be her way."

Testino, who's shot Gisele Bundchen, Gwyneth Paltrow, Madonna, and many other big name stars, told the paper that he looks for personality over physical attributes in his subjects: "With my camera, I look inside the person. If it was the surface only, my photos would be so boooooring."