The photographs of his wife and seven children show how Danish traditions were maintained, for example in the children's clothing, while his photographs of the mills document the industrial evolution of the islands. Some of these were presented at the Hawaiian Government Exhibit at the Paris Exposition of 1889, demonstrating not only the progress of the plant, but also the industrial transformation of Hawaii. In January 1889, Hedemann was one of the founding members and the first president of the Hawaiian Camera Club, which brought amateur photographers from Honolulu together with those he had met during his travels around the islands. The club gave Hedemann the opportunity to follow and experiment with the latest techniques such as magnesium powder flash photography and photographic enlargements as well as the use of the so-called magic lantern. In 1892, when he first returned to Denmark, Hedemann took his lantern slide projector with him in order to show his new home to his family and friends.