who are Krogness and Stormer?

Answer 1

Professor Carl Størmer used a camera he constructed himself, in fact the made the first cameras suitable for northern lights photography and his design soon became the most popular tool in the scientific community for northern lights research in the beginning of the previous century. In fact, it remained in use until the 1950s.

He used a light sensitive, German-made 50 mm f/2 lens (Ernemann of Dresden), along with some fast French photographic plates (Lumière étiquette violette). In 1915 he changed the objective to an Astro RK lens with an f/1.25 rating.

The cameras design, meant that he could take six - later eight - exposures of the aurora on one 9 * 12 cm photographic plate, just by moving the lens.

Størmer alone took more than 100,000 photographs with his camera.

You can see a photo of the camera if you follow this link.

A fellow Norwegian, O. A. Krogness, was responsible for the technical and practical construction of the camera.