In 1986 David began attending courses at the Art Students League in New York City and continues to retreat there every year for an intense month of drawing and painting. It was at the Art Students League that David first met and studied under internationally-acclaimed artist David Leffel. It is easy to see the influence that Leffel has had on David. Similar to the Old Masters’ style of chiaroscuro painting, most of Riedel’s works are characterized by their deep background color, lending a certain vibrancy and energy to his subjects. His use of dramatic lighting and rhythmic color, combined with a sense of solid composition, produces work that is timeless in its appeal. During 1993-1994 David lived for six months in Nepal, India and Tibet, traveling and studying the culture and language. Walking and sketching along the way, Riedel found the spontaneous portraits done in tea shops, amid roadside landscapes and in the bustling monasteries to be the most exciting and rewarding usage of his skill and talent as an artist.