Edward Woods , Sep 03, 2009; 06:19 a.m.
Rupa, I use my depth of filed preview button all the time if the goal is for the greatest depth of field and I may preset the focus manually guestimating my distance as a starting point with the awareness that I am trying to obtain the hyper focal setting empirically. I stopped using my DOF calculator when my Palm pilot died a few years ago but often wished had still had it. If you really want to know the distance then a range finder from Adorama, B&H or Cabelas may be something you will want to use to determine the correct distance away from your camera and then spot focus on that point with your camera. Perhaps the next step in digital imaging will be to add distance information to the focus point. You can find an inexpensive range finder for $150. Good hunting. Andy