Depth of field

Within the first week of my apprenticeship as a Royal Air Force photographer in 1966, we were taught that the correct viewing distance of a twodimensional work of art, like a photograph or painting, is between twice and six times the diagonal of the object in order to appreciate the message. If viewed too close you will only see the detail; if too far you will be distracted by the surroundings. Any photograph will appear unsharp if viewed close enough. Where does the viewer stop to inspect the sharpness of a photograph? A magnifying glass? A microscope? Or a scanning electron microscope? Many judges are too fixated about the technical detail of photographs and fail to enjoy the stories in them. John Heywood