Art historian Karin Lelonek works as a curator and author for a number of museums and cultural institutions. She specializes in 20th-century photography and architecture. Graphic designer, photographer, and collector Marc Walter (1949-2018) specialized in vintage travel photographs, particularly photochromes, of which he held one of the world's largest collections. He published numerous books featuring images from his collection as well as his own photographs. Sabine Arque is a photo researcher, editor, and author. She has collaborated on numerous publications on the themes of travel, the history of tourism, photochromes, and photography.