But if we are to be helpful......... the information you desire is found on page 41 of the user manual.The Nikon d3100 has a grid. It should tell you how to use it in your manual.
Look at the illustration again. There are three vertical lines and three horizontal lines. That will be your RoT guidelines. Where the lines intersect are the power points. The grid/guidelines are for a visual aid only while composing (framing) your shot while looking through your viewfinder. They do not transfer to your image.hello !!
page 41 speaks about a framing grid but it's not 3 by 3
can i use the framing grid on page 41 while taking the photo? is it applied after taking the photo?