Today is DOF day🙂 I’m wandering around DOF calculation formulas and had a look on what kind of results Wolframalpha could give. In fact, the search engine provide a complete calculation solution ! You can try it here. The interesting point is the description of the equation and a graph materializing the portion of a scene that appear sharp in a photo. Would be very useful to have such graph in the DOF calculators available for handheld devices. A simple picture is more explicit than a dozen of numbers.