His method used the camera obscura to capture architectural proportions. He often worked over a grid to ensure buildings sat correctly within the frame. He adjusted the scale of monuments to match how the human eye perceives them rather than how a camera records them. This technique created panoramic vistas grounded in truth. He populated these scenes with figures and animals to provide a sense of scale.

Collectors value van Wittel as the father of the veduta genre. His works are historical records of a Rome altered by modern development. His views of the Castel Sant'Angelo or the Colosseum offer a window into the eighteenth-century city. These prints provide order and clarity. They suit contemporary interiors that require classical subject matter and a clean, observational style.