Take a picture after 30 seconds.

App.js

const PHOTO_INTERVAL = 30000;
const FOCUS_TIME = 3000;

class Autoshoot extends React.Component {
  componentDidMount() {
    this.countdown = setTimeout(
      this.takePicture,
      PHOTO_INTERVAL
    );
  }

  componentWillUnmount() {
    clearInterval(this.countdown);
  }

  ...
}