“The camera obscura is an optical device that projects an image of its surroundings on a screen.” (via Wikipedia) It is thought that old masters like the Dutch painter Johannes Vermeer used it to create their paintings. British artist and art historian David Hockney did intensive research on the subject and concludes that the great masterpieces were created with the help of optics and lenses. (read the article on PetaPixel)
Knowing this doesn’t make their work less amazing. One can use optics and lenses and still doesn’t know anything about composition and light. One needs to be able to see first and that explains even more why a photographer can learn composition from looking at their masterpieces. They used photography tools the same way photographers are creating their compositions nowadays. So, going to a museum and looking at the old masters is a great photography lesson. Do the Louvre and you have a whole photography course, add a photographic safari and an intensive course in natural light will finish it up. And as a result your photographs are paintings with light, maybe even masterpieces of light and composition. You actually learned from old masters.
Surprising? Check it out. You can also visit the Louvre online. Here the link: Louvre.