I asked myself a little while ago, “what is the single biggest attribute” that makes a “Photorealistic Image” look “Photorealistic”. All of the following individual attributes contribute to the overall Photorealistic effect: Colour ~ Perspective ~ Lighting ~ Textures ~ Shadows ~ Reflections and Scenery etc, but not all of the above put together can't give the same visual impact as “ depth of field ”. Depth of field is part of our every day existence. It is very subtle on one hand and yet so dramatic on the other. But first, a little bit about depth of field : If you are a photographer you will know exactly what depth of field is. If not, try holding a finger at arms length and a finger a few inches away from your eyes and make like you are aiming a rifle. You cannot see both fingers at the same time in focus. You can actually feel the muscles in your eye changing the shape of the retina in order to change the focal length of the lens in your eye to focus on one or the other fingers (but you will not be able to focus on BOTH at the same time). This is depth of field . The technical reason for this and why it happens are outside the scope of this example, but depth of field is a function of focal length and aperture size. Just like the SLR camera settings. Nearly all Photorealistic Images suffer from the same affliction, “perfection”. What's wrong with perfection I hear you say! Let me explain what I believe is wrong with perfection. Have you noticed when looking at a Photorealistic image of an interior or exterior, EVERYTHING is in perfect focus. I don't know of a camera that can do that. What no camera can do, and come to that, what no human being can do, is focus all objects in a room that are at differing distances on the retina simultaneously