Beginning in 2018, during a residency at Künstlerhaus Bethanien, Österholm shifted his focus to include artificial illumination and its impact on the night skies. Urban illumination means that a star-filled night sky becomes inaccessible to more and more people all over the world due to light pollution, or the fading of our collective night sky. In Österholm’s works Antique Skies, he uses the light fitting of a street lamp to make analogue prints from historical negatives in his studio, reproducing such sections of the night sky that have become invisible as a result of light smog of the 20th century.