Shady past

David Hockney: It is a kind of joke, but I really mean it when I say Caravaggio invented Hollywood lighting. It is an invention, in that he quickly worked out how to light things dramatically. I’ve always used shadows a bit, because that’s what you need below a figure to ground it, but mine are more like Giotto’s than Caravaggio’s. I use shadows that you see in ordinary lighting conditions; you don’t find ones like Caravaggio’s in nature.

But there are other varieties of Hollywood lighting. The ‘Mona Lisa’ is one of the first portraits with very blended shadows. That face is marvellously lit, the shadow under the nose, and that smile. The soft transition from the cheekbone down to underneath the jaw is extraordinary. The way that you move from the light to the dark flesh is through incredibly subtle, graded paint that would have taken a long time, technically, to put on. I’ve no idea how he did it. You don’t quite see it in nature, but you certainly do in optical projections. Those unbelievably soft gradations look photographic. That’s what makes it remarkable, and why she has that enigmatic smile. It is a haunting face.

Oil paint lends itself to blending far more than fresco or tempera. Masaccio does blend colours in the Brancacci chapel, but the fresco medium he used is like acrylic where you have to use little linear techniques to achieve this.

It is interesting that shadows are almost exclusively European. Few have pointed it out. Most art historians, who are Europe-centred, don’t realise that there are virtually no shadows in Chinese art, nor Persian or Japanese. They are one of the things that make the major difference between western art and the art of anywhere else. They are incredibly important.

Martin Gayford: It is true that shadows are seldom seen outside western art, and where they are — as in the faint shading visible in the murals of the Ajanta Caves in India — they may represent an echo, equally faint, of ancient Greek art carried eastwards by the armies of Alexander
the Great.