Shaking their fists, 9pm

When Monet painted his series of Rouen cathedral, he had to set up a new canvas and palette for every hour of the day because of the constantly changing light. Think of the hassle.

These days, of course, we have iPads, and we can simply open a new file for each new painting. Assuming, of course, we have the patience to sit and paint anew for each hour of changing light.