Notes:
This is an example of illusionary plasticity. A photograph is a flat, two-dimensional plane. The image is rendered by the photographer using a visual language the viewer can mentally interpret and understand. In this example, the image is flat, but the converging lines of the staircase indicate a third dimension in which the stairs are rising and moving away from the viewer.
This photo would be a better example of illusionary plasticity if, when taking the picture, I had moved the focal plane back towards me. This would make the topmost stairs less defined and increase the perception of distance.
Even though much of this photo is in focus, it is not an example of tactile plasticity.