The first person to raise the possibility that Vermeer used a camera obscura was American artist Joseph Pennell, who in 1891 noticed that the man in the foreground of Officer and Laughing Girl was shown nearly twice as large as the girl he sat facing, in much the same way that such a scene might appear in a photograph.
In 2002, Philip Steadman further explored this theory in Vermeer’s Camera: Uncovering the Truth Behind the Masterpieces. (It was a lecture by Steadman in 2007 that inspired Jelley to begin the research that led to Traces of Vermeer.)
Artist David Hockney also famously made his case on the matter, with help with from physicist Charles Falco, in their 2001 book Secret Knowledge: Rediscovering the Lost Techniques of the Old Masters. To further his point, Hockney made a number of portraits using the techniques he claimed were employed by the likes of Vermeer.
In her book, Jelley is quick to allay fears that Vermeer’s use of the camera obscura diminishes his genius. Rather, she says, it is an impressive innovation. “The image from the camera obscura is merely a projection. To capture and transfer this to canvas requires skill, judgment, and time; and its product can only ever be part of the process of making a painting,” she writes. “We can never know if Vermeer worked this way; but we should remember that this is not a mindless process, and not a shortcut to success.”
Source : Did Vermeer Trace His Golden Age Masterpieces? An Artist Puts the Theory to the Test | artnet News