50mm film has its origins in the transition to sound. With sound-on-disc systems, sound was added to the silent image from a discrete source. Sound-on-film systems, however, placed the soundtrack alongside the image track, reducing the image in width from the standard 1.33:1 aspect ratio to 1.15:1. In an attempt to reproduce the standard ratio, projectionists cropped the tops and bottoms of the sound-on-film image and used a special lens to magnify that cropped image so it filled the former screen. Engineers and cinematographers objected that this magnification resulted in images with visible grain. Wide film was a way of generating a better projected image without excessive magnification of film grain. (Allan, 1930) At the same time, large movie palaces with long throws and larger screens had also resulted in a magnification of the image that pushed the limits of the standard 35mm film emulsion. (Stull, 1930)  

The 50mm wide film format also accommodated the 2mm width soundtrack used for standard 35mm release prints. Engineers also saw 50mm film as an answer to the impending threat of television, providing audiences with a big-screen entertainment format that was clearly superior to the television screens of the period which were both small and lacking in sharpness. (Belton, 2009). In response to the call for a larger film format, Hollywood turned to the Society of Motion Picture Engineers (SMPE) to come up with an industry-wide standard for wide film. Each studio was working on a different wide-film process. Metro-Goldwyn-Mayer and Fox were making films in 70mm. Warner Bros. and United Artists had begun filming in 65mm film. RKO developed Natural Vision in 63.5mm (2.5 in), while Paramount had a 56mm system called Magnafilm.

On January 27, 1930, the Standards and Nomenclature Committee of the SMPE set up a subcommittee to explore a possible standard for wide film. This committee was chaired by M. C. Batsel, an engineer at RCA Photophone. Arthur Hardy, chair of the Standards Committee, instructed it to do something about “the wide film situation”, emphasizing “the necessity of deciding on a wide film layout with the least possible delay” and reminding members that “If the SMPE is ever to be of any service to the industry, it is certainly right at this time.” (Hardy, 1930)

The subcommittee consisted of several members who were affiliated with Fox and the 70mm standard and some who were affiliated with the Warner Bros./Paramount faction that favored 65mm. After seven meetings spaced over a period of three months, the subcommittee, whose members worked for studios that were promoting wide-film formats as various as 70mm (Fox), 65mm (Warner Bros.), 63.5mm (RKO) and 56mm (Paramount), was unable to agree on a standard for either a wide-film gauge or an aspect ratio. At one point in the deliberations, E. I. Sponable, chief engineer at Fox, suggested a format of 67.5mm, attempting to establish a compromise between the competing formats, but this failed to produce any results. (Sponable, 1930)

When the subcommittee met later in October, it abandoned its earlier focus on 70mm and 65mm and began to explore other possibilities. On October 16, 1930, camera manufacturer Ralph Fear suggested that an intermediate film gauge between 70mm and 35mm might be more suitable for the majority of existing motion picture theaters. Fear suggested 50mm as a standard and the subcommittee agreed that 50mm film could satisfy the wide-film needs of the largest theaters as well (Anon., 1930b). As the subcommittee reported in its summary of Fear’s comments:

“the problem of a satisfactory wide-film layout has been under consideration by this committee for some time, and previous reports have discussed its many obvious advantages and its economic limitations, due in part to the existence of a large amount of 35 mm. equipment. This committee has felt that the adoption of release prints having a width of 65 or 70 mm. is economically impractical and has, therefore, been working for some time on an intermediate film size that would have most of the advantages of the wider film but that could be used interchangeably with 35 mm. film in existing projectors after suitable alterations. As indicated in our last report, the ratio of picture width to height is constrained by the balcony cut-off and proscenium arch in existing theaters to be in the neighborhood of 1.8 to 1. The combination of a picture of these proportions, the feature of interchangeability with 35 mm. films, and provision for a soundtrack of adequate width with suitable margins leads to a film approximately 50 mm. wide.” (Hardy, A. C., 1931).

The new standard, however, was not officially submitted for formal approval “due to the present lack of interest in wide film on the part of the producers.” 

At Fox in August 1931, Sponable converted some 70mm equipment to 50mm so that he could film test footage – which he did on A. J. Hallock's duck farm in Speonk, Long Island, NY (Bragg, 1931). Sponable tried to interest Fox in using this converted equipment to film “library” material or stock footage, arguing that it would provide higher-quality images for process shots (Sponable, 1931). Sponable put together a demonstration film on 50mm in June 1932. 

In May 1930, the major studios involved with wide-film experimentation met at the Hays Office and agreed to limit their testing of new formats until an independent expert could evaluate aIl the systems and make recommendations as to a potential standard. In December 1930, after the first batch of wide-film releases had failed at the box office, the studios, again acting through the agency of the Hays Office, placed a two-year ban on the introduction of any new formats in an attempt to prevent further costly experimentation before a standard had been agreed upon. The Hays Office agreement reasoned that a conversion to wide-film production would triple production and distribution costs as well as require the alteration and/or rebuilding of 752 of first-run theaters and all of the lesser houses in the world. Under the terms of the agreement, none of the companies experimenting with wide film were permitted to exhibit these films outside of ten key cities, severely restricting their ability to recoup the costs involved in their production and forcing them to release the films in 35mm as well (Belton, 1992). In this way, the studios themselves effectively prevented any widescreen revolution from taking place in the early 1930s.