Luminance

While reading Livingstone, Chapter 8, on luminance, I found it surprising to read that it is nearly impossible to accurately reproduce luminance in any kind of visual representation.
“No matter how good the photographic paper I use, I cannot achieve an adequate range of luminances for all the colors simultaneously! If the picture is made light enough to show the shadows on the black block, the yellow is so light that its shading doesn’t show, and the light colors appear too desaturated; if the picture is dark enough to show most of the colors accurately, the black is too dark to show shadows.”

She goes on to point out that in the picture in the book, you cannot see the luminance gradation on the yellow block. This really blew my mind because I normally think of photography as being able to capture visual images incredibly accurately. However, this is the one inevitable flaw of all visual representation. There are simply too many gradations of color due to luminance in the real world for them all to be accurately represented in an artist’s rendition.

It is also very interesting to see how different artists coped with this struggle. As Livingstone shows us with the multiple renditions of the Madonna’s red-and-blue cloak, the attempts to achieve accurate luminance are varied, yet none represent an accurate depiction, especially when placed next to the Christ Child, whose robes are significantly lighter in color and therefore show significantly more contrast between color and shadow.

However, according to John Shearman, Leonardo da Vinci was the first artist to achieve tonal unity. Da Vinci wrote, “Remember, painter, to dress your figures in lighter colors, darker colors will make lesser relief and be little apparent from a distance. And this is because the shadows of all things are dark, and if you make a garment dark, there will be little variety between the light and darks, while with light colors there will be greater variety.” He also did manage to vary the luminance of his colors without changing their saturation. Of course he did. He’s Leonardo da Vinci!