Renowned American photographer Annie Leibovitz unveiled her latest exhibition, which features portraits of women ranging from former Olympic champion and reality TV star Caitlyn Jenner, to comedian Amy Schumer, and Myanmar's Aung San Suu Kyi, in London on Wednesday 13 January. Members of the media gathered in a disused hydraulic power station in the east of the capital for the press preview of Women: New Portraits, a continuation of a project that began over 15 years ago.

Leibovitz published the popular series Women in 1999, in collaboration with writer and critic Susan Sontag. Her latest exhibition focuses on "women of outstanding achievement," according to a press release for the event. "I left journalism to go in to portraiture because I had more leeway. You're journalism you're supposed to be very objective and in portraiture, you know, you can say throw objectivity away," Leibovitz told journalists.

A photograph of Caitlyn Jenner posing in a white strapless leotard – similar to Leibovitz's photograph of Jenner on the cover of Vanity Fair published last July – is among the portraits. Caitlyn, formerly known as Bruce Jenner, changed to life as a woman in 2015. The photographer said that for her, that shoot encompassed the empathy involved in taking portraits. "It was really about the emergence, I said this before. Bruce is still there but Caitlyn emerged...I worry for Caitlyn because she has a long way to go."

American activist and writer Gloria Steinem, who features in one of the photographs in the exhibition, also attended the launch. She said that the portraits, which range from female pop stars to politicians, do not have a hierarchy. She compared it to being a circle. "You know we've been sitting around campfires for 100,000 years, telling our stories. This is another campfire," she said.

The exhibition also features photographs from Leibovitz's previous project, including a photograph of her mother, Marilyn Leibovitz, which she said was most likely her favourite photograph. She's captured many of the world's most influential women on camera, but the photographer added at the press preview that German chancellor Angela Merkel would be the next female she'd most want to photograph.

After its London launch, the exhibition will travel to several cities including Tokyo, Singapore and New York. Women: New Portraits, commissioned by UBS, is on display at Wapping Hydraulic Power Station from 16 January to 7 February 2016.