Camera.fieldOfView
var fieldOfView: float;
float fieldOfView;
fieldOfView as float
Description

The field of view of the camera in degrees.

This is the vertical field of view; horizontal FOV varies depending on the viewport's aspect ratio. Field of view is ignored when camera is orthographic (see orthographic). See Also: camera component.
	// Set the camera's FOV attached to the same game object to 60
	camera.fieldOfView = 60;
using UnityEngine;
using System.Collections;

public class Example : MonoBehaviour {
    void Example() {
        camera.fieldOfView = 60;
    }
}
import UnityEngine
import System.Collections

public class Example(MonoBehaviour):

	def Example() as void:
		camera.fieldOfView = 60

Another example using specifically the main camera:
	// Set the main camera's field of view to 80
	Camera.main.fieldOfView = 80;
using UnityEngine;
using System.Collections;

public class Example : MonoBehaviour {
    void Example() {
        Camera.main.fieldOfView = 80;
    }
}
import UnityEngine
import System.Collections

public class Example(MonoBehaviour):

	def Example() as void:
		Camera.main.fieldOfView = 80