Which of these was the first practical video camera tube?
The Iconoscope (from the Greek: εἰκών "image" and σκοπεῖν "to look, to see") was the first practical video camera tube to be used in early television cameras. The iconoscope produced a much stronger signal than earlier mechanical designs, and could be used under any well-lit conditions. This was the first fully electronic system to replace earlier cameras, which used special spotlights or spinning disks to capture light from a single very brightly lit spot.
Some of the principles of this apparatus were described when Vladimir Zworykin filed two patents for a Television system in 1923 and 1925. A research group at RCA headed by Zworykin presented the iconoscope to the general public in a press conference in June 1933, and two detailed technical papers were published in September and October of the same year. The German company Telefunken bought the rights from RCA and built the superikonoskop camera used for the historical TV transmission at the 1936 Summer Olympics in Berlin.
The iconoscope was replaced in Europe around 1936 by the much more sensitive Super-Emitron and Superikonoskop, while in the United States the Iconoscope was the leading camera tube used for broadcasting from 1936 until 1946, when it was replaced by the image orthicon tube.