スクリプトを用いてUnityのCinematicEffectのDepthOfField.csスクリプト内のパラメーターを変更したい。

Question

###前提・実現したいこと
スクリプトを用いてUnityのCinematicEffectのDepthOfField.csスクリプト内のパラメーターを変更したい。

具体的にはDepthOfField.csないの91~118行で宣言されている変数を変更したいです。下記のコードそ実行したところエラーメッセージが表示され、値を正常に取得できませんでした。

###発生している問題・エラーメッセージ

ArgumentException: GetComponent requires that the requested component 'FocusSettings' derives from MonoBehaviour or Component or is an interface.
UnityEngine.GameObject.GetComponent[FocusSettings] () (at C:/buildslave/unity/build/artifacts/generated/common/runtime/GameObjectBindings.gen.cs:38)
test.Start () (at Assets/Scripts/test.cs:17)

###該当のソースコード

私の作成したコード

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
using UnityStandardAssets.CinematicEffects;



    public class test : MonoBehaviour
    {
    private DepthOfField.FocusSettings dof;
    public GameObject came;
    private float no;
        // Use this for initialization
        void Start()
        {
        no = 10.0f;
        dof = came.GetComponent<DepthOfField.FocusSettings>();

    }

        // Update is called once per frame
        void Update()
        {
       

        if (Input.GetKeyDown("z")==true)
            {
            dof.range = no;
            }
        }
    }

DepthOfField.csのコード(全文がのせられなかったので省略)

using UnityEngine;
using System;

namespace UnityStandardAssets.CinematicEffects
{


    [ExecuteInEditMode]
    [AddComponentMenu("Image Effects/Cinematic/Depth Of Field")]
    [RequireComponent(typeof(Camera))]
    public class DepthOfField : MonoBehaviour
    {
        

        #region Settings
        [Serializable]
        public struct GlobalSettings
        {
            [Tooltip("Allows to view where the blur will be applied. Yellow for near blur, blue for far blur.")]
            public bool visualizeFocus;

            [Tooltip("Setup mode. Use \"Advanced\" if you need more control on blur settings and/or want to use a bokeh texture. \"Explicit\" is the same as \"Advanced\" but makes use of \"Near Plane\" and \"Far Plane\" values instead of \"F-Stop\".")]
            public TweakMode tweakMode;

            [Tooltip("Quality presets. Use \"Custom\" for more advanced settings.")]
            public QualityPreset filteringQuality;

            [Tooltip("\"Circular\" is the fastest, followed by \"Hexagonal\" and \"Octogonal\".")]
            public ApertureShape apertureShape;

            [Range(0f, 179f), Tooltip("Rotates the aperture when working with \"Hexagonal\" and \"Ortogonal\".")]
            public float apertureOrientation;

            public static GlobalSettings defaultSettings
            {
                get
                {
                    return new GlobalSettings
                    {
                        visualizeFocus = false,
                        tweakMode = TweakMode.Range,
                        filteringQuality = QualityPreset.High,
                        apertureShape = ApertureShape.Circular,
                        apertureOrientation = 0f
                    };
                }
            }
        }

        [Serializable]
        public struct QualitySettings
        {
            [Tooltip("Enable this to get smooth bokeh.")]
            public bool prefilterBlur;

            [Tooltip("Applies a median filter for even smoother bokeh.")]
            public FilterQuality medianFilter;

            [Tooltip("Dilates near blur over in focus area.")]
            public bool dilateNearBlur;

            public static QualitySettings[] presetQualitySettings =
            {
                // Low
                new QualitySettings
                {
                    prefilterBlur = false,
                    medianFilter = FilterQuality.None,
                    dilateNearBlur = false
                },

                // Medium
                new QualitySettings
                {
                    prefilterBlur = true,
                    medianFilter = FilterQuality.Normal,
                    dilateNearBlur = false
                },

                // High
                new QualitySettings
                {
                    prefilterBlur = true,
                    medianFilter = FilterQuality.High,
                    dilateNearBlur = true
                }
            };
        }

        [Serializable]
        public struct FocusSettings
        {
            [Tooltip("Auto-focus on a selected transform.")]
            public Transform transform;

            [Min(0f), Tooltip("Focus distance (in world units).")]
            public float focusPlane;

            [Min(0.1f), Tooltip("Focus range (in world units). The focus plane is located in the center of the range.")]
            public float range;

            [Min(0f), Tooltip("Near focus distance (in world units).")]
            public float nearPlane;

            [Min(0f), Tooltip("Near blur falloff (in world units).")]
            public float nearFalloff;

            [Min(0f), Tooltip("Far focus distance (in world units).")]
            public float farPlane;

            [Min(0f), Tooltip("Far blur falloff (in world units).")]
            public float farFalloff;

            [Range(0f, kMaxBlur), Tooltip("Maximum blur radius for the near plane.")]
            public float nearBlurRadius;

            [Range(0f, kMaxBlur), Tooltip("Maximum blur radius for the far plane.")]
            public float farBlurRadius;

            public static FocusSettings defaultSettings
            {
                get
                {
                    return new FocusSettings
                    {
                        transform = null,
                        focusPlane = 20f,
                        range = 35f,
                        nearPlane = 2.5f,
                        nearFalloff = 15f,
                        farPlane = 37.5f,
                        farFalloff = 50f,
                        nearBlurRadius = 15f,
                        farBlurRadius = 20f
                    };
                }
            }
        }


    }
}