About making pictures   - luminance study by  Waeshael


how small luminance differences produce movement.

It is hard to find the edges of the leaves, so the eyes keep moving around searching. The brain says “the leaves must be moving.” The grayscale picture shows a very small difference in the luminance of adjacent leaves, though the colors seem to be quite distinct in the original picture. This produces the idea in the brain that the leaves are moving. And to my brain, the leaves do seem to be blowing in the wind. To get this effect I allowed the leaves to become blurred by using a relatively long exposure of 1/4 second at ISO 200, which for the 600mm equivalent FL is very slow. With no hard edges to focus on, the brain creates movement of the leaves.

So, you see that sharpness in an image produces a static scene. Only by reducing luminance contrast can motion be introduced. Page back to see other examples using paintings from Monet.

Page forward to see a picture by HCB that uses the same idea.

Blowing leaves at sky blue ranch - telyt 400

luminance values