The Paramount cinematographer Joseph B. Walker is one of the first zoom lens inventors to have left a detailed account of his inventive efforts, though – as with most histories of technology – the story is rather unclear in places.
In his autobiography, Walker remarks:
Often I’m asked how the idea for the zoom lens evolved. Experimenting with lenses had intrigued me since the first time hooked through a camera. In 1922 […] I turned to one of my experimental lenses; remembering my two-lens newsreel camera of the Jesse Buffum days, it seemed a good time to explore an optical effect that had long tantalized me.
After a great deal of trial and error, Walker eventually arrived at a design he was happy with:
It worked well; the lens stayed in focus while it moved from wide angle to telephoto. The image appeared to travel through space, therefore I called it the ‘Traveling Telephoto’ lens. In February, 1929, I applied for a patent.
Walker seems to imply that he worked alone, but there is evidence that this may not have been the case. Two years before Walker filed his patent, a fellow Paramount employee named Rolla T Flora filed a patent which described: “the provision of picture-taking means having a movable lens system controllable by a single operation to have relatively short-focal, telephoto or any intermediate focal characteristics with respect to a given focal plane”
In other words: a zoom lens. It seems that Walker was not the only person at Paramount working on zoom lens technology – but there exists very little information about the activities of Rolla T Flora, or the broader optical innovations of Paramount during the 1920s, so for now this remains something of a mystery.
Later in his career, during the 1950s, Walker revived his interest in zoom lens technology. He adapted the zoom lens he had developed during the 1920s. Renamed the ‘Electra-Zoom’, the new product featured a motor which enabled the operator to zoom in or out smoothly. As American Cinematographer reported in May 1950:
The beauty of the end-result is a picture which is entirely devoid of any eye-arresting irregularities in zoom rate or picture centering. The viewing audience is therefore drawn to or carried away from the center of interest quite unaware of the mechanics or optics involved.
Due to the dominance of Frank Back’s Zoomar lens, Walker’s role in the history of the television zoom lens has been rather overlooked – but there’s little doubt that the ElectraZoom – marketed around the world by the electronics giant RCA – was a significant production tool during the early days of postwar television.
- Further reading: See Walker’s patent, and Flora’s patent, at Google Patents. Joseph Walker briefly discusses zoom lens innovations in his autobiography, The Light On Her Face (Hollywood: ASC Press, 1984). For further details of the ElectraZoom as reported in American Cinematographer see H I Smith’s article “Pushbutton Zoom lens for TV” vol. 31 iss. 5 (May 1950): pp 160+.