Nikon D3400 Triple Lens Parent's Kit Owner's Manual

67

Take the photograph.
Press the shutter-release 
button halfway to focus, 
and then press the button 
the rest of the way down. 
The self-timer lamp will 
start to flash and a beep will 
begin to sound. Two seconds before the photo is taken, the 
lamp will stop flashing and the beeping will become more 
rapid. The shutter will be released ten seconds after the timer 
starts.

Note that the timer may not start or a photograph may not be 
taken if the camera is unable to focus or in other situations in 
which the shutter can not be released.

To stop the timer 

without taking a photograph, turn the camera off.