Archived posting to the Leica Users Group, 2001/02/07
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Okay Austin, I am speechless... So you think.... You did actually read my post? ......oh well. Cheers, John > From: "austin@darkroom.com" <austin@darkroom.com> > > I disagree. If you take the same lense, and use it on ANY size film, at the > same distance, you will get the same DOF. Optics doesn't know what the film > size is, and adjust it self accordingly. 3' IS 3', no matter what the film > size is. > > I don't disagree that if you change the distance, to re-frame the image so it > is the same composition you will get different DOF, but that is not part of > the discussion...the DOF calculator keeps the same distance, just changes in > the film format change the resultant DOF it gives you. I believe that is > wrong. > >> Depth of field is a factor of image size and relative aperture. The film >> format/ lens combination affects the image size. A 45mm lens in on a 4x5 >> camera will record an object "smaller" in the final print than a 45mm on a >> 35mm camera. You could enlarge the 4x5 negative more than normally is done >> and print an identical image size (assuming you shot both cameras at the >> same subject distance) and achieve identical depth of field (and COC) but >> this is not normal practice. > >>>> http://www.silverlight.co.uk/resources/dof_calc.html >>>> >>> >>> This web page changes the DOF based on film format...why would film format >>> effect DOF? >