(continued) Check out a freeware renderer called Kerkythea. You will see that it provides parameters for adjusting camera type and exposure settings that actively affect the final render. Also it provides built-in "post work" adjustments - similar to what you might find in an image editor. The examples you have given are as much experiments with light as they are experiments with exposure. If you understand this then you'll know that the skill of the photogrpher and the instrument he/she uses is as important a dynamic as anything else in the frame. take care jdc