When you want to get in real close to your subject, you are entering the realm of the macro photographer. Usually this means you need a specialized macro lens, one that allows for extremely close focusing distances and provides a reproduction ratio of at least 1:1. For some subjects this may be your only choice, for example, capturing the minute details of an insect. For situations like that I will grab my M.Zuiko Digital...
M.Zuiko Digital ED 40-150 F2.8