Step by step Focusing from front to back
01 Set a small aperture (but not too small)
Of the three variables that influence depth of field (DOF), aperture is arguably the most important, and the one you have most control over. In order to maximise DOF, set a small aperture, but not too small (at apertures smaller than around f/16, something called diffraction actually starts to soften images). Unless it’s very bright this will result in a slow shutter speed, so use a tripod and set mirror lock-up, and use a remote release or Nikon’s two-second timer, to avoid camera shake.
02 Focus on the right area
Irrespective of focal the length you choose, always ensure that you focus accurately in order to optimise depth of field in your image. Remember that more of the scene will be brought into focus behind the focus point than in front, which means you need to focus on the optimal part of the scene (the so-called hyperfocal distance) to maximise depth of field. (See Pro Tips!, left, for more details on how to do this if you don’t have a hyperfocal distance chart to hand).
03 Swi tch to manual focus
If you use autofocus, make sure that the active focusing point is aligned precisely on the spot you want to focus on. Alternatively, use the default central focusing point to autofocus, and then lock the focus by switching your lens to manual mode, before recomposing your shot. Another option is to use Live View to magnify the image on the LCD on the back of the camera to 100% view, and then manually focus on a detail or edge that you know is on or near the hyperfocal distance.