Archived posting to the Leica Users Group, 2001/02/11
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]> Erwin has a nice page on DOF issues: > http://www.imx.nl/photosite/technical/DoF/DoF.html > > I quote out of context to pique your interest: > Erwin states: >>>>> So the calculated depth of field is eqaul on both sides. The welllknown rule that the total length of permissible sharpness extends 1/3 in front and 2/3 beyond the image plane/plane of focus is derived from the fact that many enlarged pictures are not viewed from the proper distance that is required when the perspective of the lens and at the moment of the picture is the same as that from the viewing distance. Many pictures are viewed from a distance that is too short for the proper perspective. <<<<<< So you are looking at this photograph. The depth of field is 1/3 in 2/3 out. You now move the photograph away from your face to its proper viewing distance for perspective. The depth of field is now 1/2 in 1/2 out. This seems highly counter intuitive to me.