Claude Monet had calculated that the light changes every seven minutes in Giverny. I wonder if he didn’t exagerate a little bit, but he had an exceptional eye and he wanted to render the slightest light changes exactly.
Monet painted in series. He chose a spot he liked in his garden, a special framing of his pond, and he painted it over and over again.
That is to say he had several canvases on work, sometimes ten, sometimes up to twenty. He gave a few brushstrokes on one, then he noticed that the light was changing. He would look among the unfinished canvases to find the one corresponding to this very light effect. He put it on the easel, went on with it for a few minutes. Eventually the light would change again, and Monet accordingly changed the canvas on the easel. And so on.
It was a slow process: Monet had to wait until the same light effect would come back to complete the canvas. Impressionist painters don’t imagine nor remember, they paint what they can see, the impression of the moment.
It is a challenge to paint a moment, for it takes many hours of hard work to paint a landscape. With many canvases on work at the same time, it could last monthes or even years before all of them were considered finished.