Photographer Gerd Ludwig is a lighting master with TTL strobe lights. He uses them in unusual and unpredictable ways to direct the the viewer’s eye through his photographs, convey a sense of place, and define his visual style. Yet his strobe lights are all but invisible, blending with available light sources. In this video, Ludwig explains the basics of his technique. He shows how he has applied it to images from his various assignments for National Geographic magazine, including a story about nightlife in Moscow. The images are also featured in his forthcoming book called minus 2/3: The Invisible Flash. (“minus 2/3” refers to Ludwig’s frequent TTL flash setting, which he uses to avoid overexposure that often results from full-power settings.) The book, which will ship in December, features 100 images with flash settings, color gel information, and other lighting details about each image. Ludwig will also be teaching his techniques at a seminar called “The Invisible Strobe—Updated” at PhotoPlus Expo on October 20.