You're no doubt familiar with Self-Timer mode on your Nikon D7100, which delays the shutter release for a few seconds after you press the shutter button, giving you time to dash into the picture. Here's how it works on the D7100:
After you press the shutter button, the autofocus-assist illuminator on the front of the camera starts to blink. If you enabled the camera's voice via the Beep option on the Custom Setting menu, you also hear a series of beeps. A few seconds later, the camera captures the image.
By default, the camera waits 10 seconds after you press the shutter button and then records a single image. But you can tweak the delay time and capture as many as nine shots at a time. Set your preferences through the Self-Timer option on the Custom Setting menu.
Here's what you need to know about the three settings:
Self-Timer Delay: Choose a delay time of 2, 5, 10, or 20 seconds.
Number of Shots: Specify how many frames you want to capture with each press of the shutter button; the maximum is nine frames.
Interval between Shots: If you choose to record multiple shots, this setting determines how long the camera waits between each one. You can set the delay to a half second (the default setting), 1 second, 2 seconds, or 3 seconds.
Two more points to note about self-timer shooting:
Using flash disables the multiple frames recording option. The camera records just a single image, regardless of the Number of Shots setting.
Cover the viewfinder if possible. Otherwise, light may seep into the camera through the viewfinder and affect exposure. Your camera comes with a viewfinder cover made just for this purpose.