Samsung NX1000 User Manual page 67

While youarepressing [ Shutter] h alfway, thecamera continues t o
automatic f ocusing. Once thefocus areaisfixedonthesubject,
thesubject i salways infocuseven whenmoving. Thismode is
recommended forshooting a person ona bicycle, a running dog,ora
carracing scene.
Youcanmanually focusona subject b yrotating thefocusringonthe
lens. T heMFAssist f unction letsyoueasily achieve a focus. W hile
youarerotating thefocusring, t hefocusarea is magnified or the
focus aidbarappears t o heip youachieve a clear f ocus. T hismodeis
recommended forshooting anobject s imilar i ncolortothebackground,
a nightscene, o rfireworks.