Wilse traveled extensively in Norway, both on assignment and for his own interest. He brought his 10 kg camera to inaccessible places through rugged terrain, going as far north as Svalbard.

He photographed both natural sceneries and people at work, including the fishing industry in Lofoten before the introduction of motorized boats. His photography business was also a commercial success, and he acquired among other things the entire archive of Axel Lindahl, who had photographed scenes in Norway in the 1880s and 1890s. His photos also appeared in National Geographic Magazine.