ian: "Depth of Field may also be dependent on the camera's focal length." yes, you're right - well, at least in the reality. the biger (larger, higher?) the focal length, the harder is to get the background to be blurred. if you have short focal lengths, your background will be blurry even in short distances. if you are going for realistic backgrounds with the teleobjective you must consider that your backgrounds should stay rather sharp. maybe if someone would ask in the photo forum for the right values, i don't think my english is sufficient to make myself clear ;) one question though: there is some jagginess around her hair on the shoulders and on that vertical white spot left from her head. are those compression artefacts or is this the firefly blur-algorhythm (i think i remember dimly that i saw already those things on another dof experiment)?