I recently took a few pictures at f11/f14 to be sure to have enough DOF and I just spent some time fiddling here: http://www.dofmaster.com/dofjs.html to verify if this small apertures were really needed. Here is what I found, mostly related to landscapes. At 12mm/5.6 the hyperfocal distance is 1.7 meters and the near limit is 0.9 meters. This means that unless I want something closer than one meter in focus(!) I can just not care about the focus: just avoid to focus on my feet and I should be ok. Event at 2.8 the near limit is 1.7 (focusing right behind the hyperfocal distance). And even if I focus at 20km the near limit at 5.6 does not go behind 1.7 meters. I also suppose that if a rock in the foreground is just outside of the near limit it is not going to blur that much. At 25mm/5.6 the hyperfocal distance is 7.4 meters with the near limit al 3.7. This again means that for most (landscapes) pictures I just need to set the focus behind 7 meters. Here I could have some close elements in the pictures (grass, rocks, a tree) so going to f8 and focusing at 5 meters gives a near limit of 2.6 meters. f11 gets me a near limit of 1.9 meters. A lot. At 40mm/5.6 the hyperfocal distance is 19 meters and we have 9.5 meters of near limit. f8 can push it down to 6.7 meters, f11 to 4.7, f16 to 3.4 meters. Summing up: with the 12-40, shooting at 5.6, I do not need to worry about focus unless I have really close elements in the foreground, especially on the long end of the lens. F5.6 or f8 should be good enough, avoiding most of diffraction too. Am I simplifying too much? I have read this: http://www.trenholm.org/hmmerk/DOFR.html so I know that I am simplifying a little (it explains why and when can be better to focus behind the hyperfocal distance).