int Trig = 8;
int Echo = 9;
int Duration;
float Distance;

int PhotoTakeDistance = 10; //[cm]

void setup() {
  Serial.begin(9600);
  pinMode(Trig,OUTPUT);
  pinMode(Echo,INPUT);
}

void loop() {
  digitalWrite(Trig,LOW);
  delayMicroseconds(1);
  digitalWrite(Trig,HIGH);
  delayMicroseconds(11);
  digitalWrite(Trig,LOW);
  Duration = pulseIn(Echo,HIGH);
  if (Duration>0) {
    Distance = Duration/2;
    Distance = Distance*340*100/1000000; // ultrasonic speed is 340m/s = 34000cm/s = 0.034cm/us 
    Serial.print(Distance);
    Serial.println(" cm");
//
//photo will be taken
//
    if(Distance < PhotoTakeDistance){
      Serial.println("Photo Taken");
      delay(1000);
    }
  
  }
  delay(500);
}