Turn on the camera and rotate the mode dial to "M" (manual mode) or "A" (auto mode) - depending on which mode you want to shoot in. Press the "i" (info) button on the back dial. This will bring up the camera settings display on the screen. Use the multi-selector (rear dial) or arrow buttons to navigate within the display. Find and select the "Image Area" setting. You can use the multi-selector or arrow buttons for this, and press "OK" to enter. When setting the image area, choose the "16:9" format. This can be done using the multi-selector or arrow buttons. Confirm the selection by pressing "OK". Then, go back to the previous menu and exit by pressing the "i" button again. Now, the Nikon D5100 is set up to shoot videos in a 16:9 widescreen format. After adjusting the settings, you can start recording by pressing the record button located on the back of the camera. It's important to note that during filming, you may also need to adjust other settings such as shutter speed, aperture, ISO sensitivity, and focus to achieve the desired video quality and exposure. Additionally, keep in mind that shooting in 16:9 format crops part of the image compared to the camera's native aspect ratio (typically 3:2).
