Ampex's quadruplex magnetic tape video recording system has certain limitations, such as the lack of clean pause, or still-frame, capability, because when tape motion is stopped, only a single segment of the picture recording is present at the playback heads (only 16 lines of the picture in each segment), so it can only reproduce recognizable pictures when the tape is playing at normal speed.) But in spite of its drawbacks it remained the broadcasting studio standard until about 1980. The helical scan system overcame this limitation.