Example of a clamped camera look rotation.

CameraControl.cs

		target.RotateAround (target.position, target.right, addedRotation);

		bool lookingUp = Vector3.Angle (target.forward, Vector3.up) < Vector3.Angle (target.forward, Vector3.up * -1.0f);
		float angle = Vector3.Angle (target.forward, Vector3.Cross (target.right, Vector3.up));

		if (angle > forwardAngleClamp)
		{
			target.RotateAround (target.position, target.right, lookingUp ? angle - forwardAngleClamp : forwardAngleClamp - angle);
		}