From an early age he was taught to draw and paint by his father as well as by the painter L.A. Ring who was a close friend of the family.

In 1908, an exhibition with Bertelsen's and Achton Friis' works from the expedition was featured first at Den Frie Udstilling in Copenhagen and later in Aarhus and Odense.

In 1909 it moved on to Berlin and other German cities and in 19010 it was exhibited by the Royal Geographical Society in London.

[4] In 1907 Bertelsen, together with J.P. Koch, was reported to have first seen Fata Morgana Land (Danish: Fata Morgana Landet), a phantom island supposedly lying between NE Greenland and Svalbard.

He was a co-founder of Kunst for Varer ("Art for Goods") in 1924 and was chairman of the organization until his death in 1945.