Archived posting to the Leica Users Group, 2000/11/08
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]"M.E.Berube" <MEB@goodphotos.com> wrote: > Douglas Herr wrote: > >> DOF has nothing to do with focal length. DOF is influenced >> by image magnification and aperture. Shorter lenses have >> greater DOF for a given aperture and working distance >> because of the reduced image magnification. > > OK. > Aren't lenses that are "Shorter" and have "reduced image > magnification" usually pretty much reciprocal with Wider > Angle focal length lenses? (I'm honestly trying to gain > new knowledge with this question.) At the risk of running this thread into the ground, here's another way of looking at it. Choose two lenses of different focal lengths, say a 35mm and a 90mm, set 'em both to a fairly large aperture like f/4, aim 'em from the same location at the same target, focus on the exact same point and take photos with both. The 35mm photo will have greater DOF due to its wider angle of view. But it includes more stuff too. Now if you make an enlargement from this photo equal to the 90's angle of view you'll find the enlargement's DOF is identical to that of the photo made with the 90. So if you want more DOF (from a camera lacking movements) within a given composition and for a fixed point-of-focus you can only get it by stopping down to a smaller aperture. - -Dave-