Nikon D3100 D3100 User's Manual - Page 76

Focus Point Selection In manual focus mode or when autofocus is combined with AF-area modes other than e (Auto-area AF), you can choose from 11 focus points, making it possible to compose photographs with the main subject almost anywhere in the frame. 1 Choose an AF-area mode other than e (Auto-area AF; 0 58). 2 Select the focus point. Use the multi selector to select the focus point in the viewfinder or information display while the exposure meters are on. Press J to select the center focus point. z Focus point Focus Lock Focus lock can be used to change the composition after focusing in AF-A, AF-S, and AF-C focus modes (0 55), making it possible to focus on a subject that will not be in a focus point in the final composition. If the camera is unable to focus using autofocus (0 56), you can also focus on another subject at the same distance and then use focus lock to recompose the photograph. Focus lock is most effective when an option other than e (Auto-area AF) is selected for AF-area mode (0 58). 1 Focus. Position the subject in the selected focus point and press the shutter-release button halfway to initiate focus. Check that the in-focus indicator (I) appears in the viewfinder. 60