He had an affectionate nickname of Wizard of Tuorla (Observatory/Optics laboratory), and a book with the same title in Finnish describes his works.

[1] Once he saw Schmidt's publication, he promptly went ahead and "solved" the field flattening problem by placing a doubly convex lens slightly in front of the film holder – back in the 1930s, astronomical films were glass plates (also see photographic plates).

Prof. Väisälä made a small test unit of 7 mirrors in a mosaic on stiff background steel frame, however it proved to be impossible to stabilize as "just adjust and forget" structure, and next time anybody tried it, was with active controls on Multiple Mirror Telescope.

In the 1920s and 1930s Finland was doing its first precision triangulation chain measurements, and to create long-distance vertices Prof. Väisälä proposed usage of flash-lights on 5 to 10 kilometres (16,000 to 33,000 ft) altitude balloons, or on some big fireworks rockets.

Prof. Väisälä also developed excellent tools to measure earth rotational axis position by building so called zenith telescopes, and in the 1960s Tuorla Observatory was in the top rank of North Pole position tracking measurements.

In the 1980s radioastronomy was able to replace Earth rotation tracking by referring things against "non-moving background" of quasars.

For this rather massive photographic survey work, Prof. Väisälä developed also a protocol of taking two exposures on same plate some 2–3 hours apart and offsetting those images slightly.

[7] Together with Liisi Oterma he co-discovered the Jupiter-family comet 139P/Väisälä–Oterma, which was first classified as asteroid and received the provisional designation "1939 TN".