The problem of Nikon d800.

? Self-timer steps: 1. Put the camera on a tripod; 2. Select the self-timer mode (there is a mode dial on the left shoulder of the camera, press the dial lock release button in front of the mode dial to turn the mode dial to the self-timer mode small alarm icon); 3. Composition and emphasis; 4. Press the shutter completely and start taking a selfie. After 10 seconds, the shutter will automatically release to finish shooting. This method is on page 106 of the specification.

? If you are inexperienced in taking group photos, the camera settings are as follows: choose aperture priority mode, and set the aperture above F8 to ensure sufficient depth of field; The sensitivity is set to automatic (so that the shutter time will not be too slow); Use the single-point AF area focusing mode (I often use the single-point focusing mode, which is very convenient when I get used to it, and Nikon's multi-point focusing is suitable for moving snapshots), select the subject person (or middleman) to focus, press the shutter for half a turn to focus, indicating that the focus is successful, and then press the shutter completely to shoot.

? I hope my answer is helpful to you.