Ever since he took up photography, more than 40 years ago, Mario Testino has been in perpetual motion—circling the world, working weekends, constantly jetting to just about anywhere. With his latest exhibition, “South Americana,” on now at Hamiltons Gallery, in London’s Mayfair, the Peruvian-born photographer makes a triumphant return to his home hemisphere.

What drew Testino, master of portraiture and the fashion shoot, back to Latin America? Gravity, of a sort. In the last decade, he has increasingly focused on projects in his native Peru. “I started being a photographer in England, and I was so in awe of the English and their culture, so at first I tried to emulate them,” Testino tells AIR MAIL. “But I’m not English and I never will be. I needed to go into my essence to really discover who I was and find the ‘Mario Testino’ photograph.” In this dazzling new show he celebrates the culture that formed him, breaking new ground in the process.

The surprises begin in the first gallery at Hamiltons, where vaqueros (cattle herders on horseback) tear across the grassy plains of Colombia’s Llanos region. One twirls a lasso overhead; another canters into the distance. Coal-black silhouettes against brilliant tangerine sunrises, these cowboys are abstract figures of pure power, deftly maneuvering their steeds beneath a limitless sky. Self-consciousness, attitude—inevitable by-products of fame and high style—are nowhere to be found in these images. Neither man nor beast even looks in the camera’s direction.

Cactuses by Testino.

The second gallery at Hamiltons features sensual images of cactuses, of all things, scaled large. In Testino’s hands these modest succulents—ubiquitous in the Southern Hemisphere—reveal a dynamism all their own. Some are round and spiked; others exuberantly lanky and less forbidding. When Testino shoots them in pairs, they seem to engage in dialogue.

This is all far removed from his earlier work, those glamour shots that chiseled beneath the surface. Most famously, there was the tender, winsome version of Princess Diana peering out from a Vanity Fair cover, July 1997, guilting the world into seeing her in a more sympathetic light. Or that other defining Testino image, from 2007, of a leggy female swathed in sequins, folding herself into a pale limousine. It’s yet another glimpse of raw power, one that helped to transform a novice named Gisele Bündchen into a supermodel.

Like other renowned photographers who’ve seen their names become a bit too synonymous with fashion, Testino, in this later stage of his career, is now creating something closer to pure art. And it’s of a distinctive Latin American kind, with all of the implied exuberance, movement, and color. These works pulse with joyous energy. Testino’s cactuses dance; his silhouetted riders rocket into space. Clearly, he’s come home. —Penelope Rowlands