Recently, I mentioned the book on Gustav Klimt's landscapes. When painting outdoors, he would often use binoculars or a telescope to view his landscape. This gave him unusual vantage points. It's similar to today's practice of using a digital image, which one can enlargen and trim on a computer.
This weekend my wife showed me a cartoon by Dave Coverly, which appeared in Parade, an insert usually found in the Sunday papers. It shows an artist working at his easel painting a still life. He is looking at a table to his left, which holds his laptop. The laptop has an image of a still life!