Cornelius would operate two of the earliest photographic studios in the United States between 1841 and 1843. His studio achieved improved photographic quality through the implementation of reflectors to direct additional light onto the portrait subject and blue glass filters. These changes along with improved photographic plates allowed portrait subject to only have to remain still for about one minute. His studio became popular with wealthy patrons and many of his portraits of famous people still exist. As the popularity of photography grew and more photographers opened studios, Cornelius either lost interest or realized that he could make more money at the family gas and lighting company.