The name of System Petersen and Poulsen became known all over the world
After 5 years, however, the first film was produced. On the 12th of October, 1923, the first sound film recorded indoors was shown at the Palace Theatre in Copenhagen. It was the first real sound film, recording using the “variable area” method. For the first time the name of System Petersen and Poulsen was on film strip. The name was later to be known all over the world.
At that time two films were run simultaneously - one with pictures and one with sound (i.e. it was necessary to synchronize the two machines). Nevertheless the first performance was met with enthusiasm, and it became the method for presentations in the whole of Europe while licenses were established for this technology in many other countries. Later in the twenties the System Petersen and Poulsen was also adopted by the largest American film productions. By that time, the problem of synchronization of picture and sound on the same strip was solved. This became a common requirement on the part of the producers to simplify the copying and editing of the films.
Also within this field the two Danish engineers succeeded in achieving eminent results. Several of the cameras and recording heads constructed then for cinema projectors, were still employed as late as 1968. Additionally a number of other appliances, such as condenser microphones, dynamic compressors, oscilloscopes, optical instruments, amplifiers for reproduction and studio equipment with mixing and editing tables were developed.
The fact that improvements can be noticed without any advance publicity was certified at a Danish premier in 1944. The press wrote that the film was boring but the sound surprisingly good. Electrical Phono Films A/S had constructed a new dynamic compressor which was used for the first time; later this compressor was patented.