These three terms have always confused me…I’ve always thought that shallow DOF was the subject nearest was in focus….I thought narrow DOF was just that, narrow, anywhere in the frame….Bokeh, to me, has always meant that the out of focus background was somewhat recognizable, or something contrasty/interesting
I could be wrong, but ‘bokeh’ is more a subjective evaluation of the quality of the out-of-focus areas. Doughnuts are usually evaluated poorly, as are obvious signs of the aperture blades. Some folks get pretty crazy with the evaluations and swear by Leica or Zeiss optics, but I know that my 70-200mm f4 L has better bokeh than my 24-85mm non-L, so those folks are probably onto something.
A shallow DOF can be shown with a distant subject, but the way optics work, the zone-of-focus increases as subject distance increases. That means that “shallow” is hard to show for, say, mountains. Not sure what “narrow” DOF is, if it isn’t “shallow”.
