David Hockneys Secret Knewledge

David Hockneys Secret Knewledge is a BBC world documentary dating from 2003. 

We follow the artist David Hockey which discussed his theory that artists were secretly used optical devices such as mirrors and lenses in creating their work as early the 15th century. 

Hockney's studio is in Hollywood. He realized his own Renaissance Florence and Bruges. He took us 6 century ago, and as him, when we see a painting from 15th century, we see a " real, natural " photographic which comes to life. We are surprised how painters did. There is a real contrast between before 15th century and after. There are many incredible details. Like the folds in the fabrics, the shine from armors of war. Some are not correct and few years after some seems really real. Like the painting of Van Dyke's, the chandelier and the mirror's details. 

Painters used a darkroom also called a camera obscura. In this darkroom there is a hole which lets light. On this hole, there is a lence and the outside picture is projected on the wall inside, upside down. 

The eyes don't go out of focus. It´s not blurred. So that shows that artists used lences in 1540s. There is no written because painters which had lenses, considered that was a secret and kept secret. 

Hockney is interessed by art history. He also makes comparisons between paintings and digital imagery.