With so many movers and shakers gathered at the Fortune Most Powerful Women Summit in September, we jumped at the chance to capture some of them on film. Xerox CEO Ursula Burns, McDonald’s USA COO Jan Fields, and Google VP of Search Products and User Experience Marissa Mayer are among the portraits you’ll find in this gallery, shot by another notable woman, photographer Robyn Twomey. A regular contributor Fortune, Twomey also shot Bill Gates Jr. and Sr. for the cover of our Best Advice issue this year. –Jessica Shambora