How did Johannes Vermeer use pinholes and strings to create perspective?

It is a common misconception that Johannes Vermeer used a camera obscura to trace his compositions directly onto a canvas. While he was fascinated by the optical effects produced by such devices, technical evidence suggests he relied on traditional perspective construction methods to achieve his sense of space.1

In many of his interior genre scenes, researchers have discovered small pinholes located at the vanishing point of his perspective system. Vermeer likely used these pinholes as anchors for strings, which served as guides to construct the orthogonal lines that define the recession of architectural elements such as floors, windows, and walls. By carefully positioning this vanishing point, Vermeer was able to emphasize the primary compositional elements of his paintings, such as the hand of the figure in Woman Holding a Balance.12