How did widescreen movies come about?

In the 1950s, many attempts were made to make movie theaters more competitive with television. Among them, with the rise of three-dimensional movies at that time, large-screen cinematography systems also began to be used in that era. Filmmakers began using 35mm-wide tape in some systems; 70mm-wide tape in others. French scientist Henri Chrétien developed an anamorphic lens that allowed a camera to compress a wide image onto film and expand it when the film was projected through a projector. It was not until the 1950s that American inventor Fred Waller invented true widescreen stereoscopic cinema, although the system he invented required three cameras and projectors that were running simultaneously to work together.