The S01 will automatically switch to Close-Up Mode when it senses that its appropriate for the subject. The focus range for this mode is 5cm to infinity at "W" and 50cm to infinity at "T". If the focus indicator turns green but your pictures are still blurry, you may be experiencing motion blur. Motion blur will occur if the camera slows down the shutter speed to compensate for shooting without flash in low light. To resolve this you can try enabling the flash or steadying the camera by resting it on a stable surface.
Please see page 14 of the S01 manual for details on other situations that may impair the camera's ability to focus. A copy of the S01 manual can be downloaded from here:https://support.nikonusa.com/app/an...
If you continue to have trouble please contact Nikon Support: http://support.nikonusa.com