Ever taken a picture and wished that either more of it had been in focus or the exact reverse and that less had been in focus? Of course you have I certainly have. But what settings on your camera give which results and what if you change one of those settings what is the Depth of Field then. You can calculate it all yourself but it is not easy. This App takes all of those problems and makes it easy to find the answers. Just type in the distance to the subject, the focal length being used and the f-stop and the App calculates the near and far distances of acceptable focus and therefore the depth of field. This is all shown on an easy to understand diagram.
An example is: You are trying to take a photo of a bee on a flower and all but the bee is to be out of focus. Set the distance of the subject to be 200 mm (20 cm, approx 8 inches), set the f-stop to be f/5.6 and set the focal length at 50 mm. The App calculates that the depth of field is 3.41 mm (0.