The set up procedure as outlined in the instructions is fairly straight-forward. You might try going back into your set up and reset the video time for the 15 mins. that you want. If this doesn't work, your video might be malfunctioning. Press ON, press OK, press MENU, press OK, then up/down until you reach the setting: VIDEO - OUTPUT SETTINGS: VIDEO TIME: 3, 4, 5, 10, 15 Minutes per file. After each selection press OK (this is important) to confirm. Press MENU to leave one menu item for another and then again to EXIT.