Two major defects

This product has two major defects: First, the distances are only in the metric system, and for us provincials, the conversion, particularly for near objects, is more difficult than it should be; Second, and more importantantly, the near focussing distance is 4 meters, which is much too far for serious landscape photography, where a near object, within a foot or two of the lens, is very important to the composition.

AustinCarey about f/8 DoF Calculator, v1.4.5