react-native-vision-camera/docs/docs/guides/FOCUSING.mdx

---
id: focusing
title: Focusing
sidebar_label: Focusing
---

To focus the camera to a specific point, simply use the Camera's [`focus(...)`](/docs/api/classes/Camera#focus) function:

```ts
await camera.current.focus({ x: tapEvent.x, y: tapEvent.y })
```

The focus function expects a [`Point`](/docs/api/interfaces/Point) parameter which represents the location relative to the Camera view where you want to focus the Camera to (in _points_). If you use [react-native-gesture-handler](https://github.com/software-mansion/react-native-gesture-handler/), this will consist of the [`x`](https://docs.swmansion.com/react-native-gesture-handler/docs/next/gesture-handlers/api/tap-gh/#x) and [`y`](https://docs.swmansion.com/react-native-gesture-handler/docs/next/gesture-handlers/api/tap-gh/#y) properties of the tap event payload.

So for example, `{ x: 0, y: 0 }` will focus to the upper left corner, while `{ x: VIEW_WIDTH, y: VIEW_HEIGHT }` will focus to the bottom right corner.

Focussing adjusts auto-focus (AF) and auto-exposure (AE).

:::note
`focus(...)` will fail if the selected Camera device does not support focusing (see [`CameraDevice.supportsFocus`](/docs/api/interfaces/CameraDevice#supportsfocus))
:::

## Example (Gesture Handler)

This is an Example on how to use [react-native-gesture-handler](https://github.com/software-mansion/react-native-gesture-handler/) to focus the Camera to a specific point on the screen:

```tsx
import { Camera, useCameraDevice } from 'react-native-vision-camera'
import { Gesture, GestureDetector } from 'react-native-gesture-handler'

export function App() {
  const camera = useRef<Camera>(null)
  const device = useCameraDevice('back')

  const focus = useCallback((point: Point) => {
    const c = camera.current
    if (c == null) return
    c.focus(point)
  }, [])

  const gesture = Gesture.Tap()
    .onEnd(({ x, y }) => {
      runOnJS(focus)({ x, y })
    })

  if (device == null) return <NoCameraDeviceError />
  return (
    <GestureDetector gesture={gesture}>
      <Camera
        ref={camera}
        style={StyleSheet.absoluteFill}
        device={device}
        isActive={true}
      />
    </GestureDetector>
  )
}
```

<br />

#### 🚀 Next section: [Exposure](exposure)