Johnston was born into an affluent New York banking family, which subsequently moved to
Mount Vernon, New York
. Initially he studied painting and illustration at the
National Academy of Design
in New York, but after graduating in 1908 (and marrying fellow student Doris Gernon the next year), his subsequent efforts to earn a living as a portrait painter did not meet with success. Instead, reportedly at the suggestion of longtime family friend and famed illustrator
Charles Dana Gibson
, he started to employ the camera previously used to record his painting subjects as his basic creative medium.
In approximately 1917, Johnston was hired by famed New York City live-theater showman and producer Florenz Ziegfeld as a contracted photographer, and was affiliated with the Ziegfeld Follies for the next fifteen years or so. He also maintained his own highly successful personal commercial photo studio at various locations around New York City as well, photographing everything from aspiring actresses and society matrons to a wide range of upscale retail commercial products
