how to use ScreenPointtoRay and PhotonNetwork.isMine?

Options
is have this code:
void Update () {

raio = cam.ScreenPointToRay (Input.mousePosition);
mira (raio);

}

#region implemented abstract members of AbsMira

public override void mira (Ray raio)
{
if (Physics.Raycast (raio, out ponto, 5000F)){
transform.LookAt (this.ponto.point);
} else {
this.frente = this.cam.transform.position + raio.direction * 2500F;
transform.LookAt (frente);
}
}

the problem: i need use the photonView.isMine BUT the camera isn't instantiate. how i do this?
tanks.