SceneViewFilter.cs

using UnityEngine;
#if UNITY_EDITOR
using UnityEditor;
#endif

// http://framebunker.com/blog/viewing-image-effects-in-the-scene-view/
public class SceneViewFilter : MonoBehaviour {
#if UNITY_EDITOR
    bool hasChanged = false;

    public virtual void OnValidate() {
        hasChanged = true;
    }

    static SceneViewFilter() {
        SceneView.onSceneGUIDelegate += CheckMe;
    }

    static void CheckMe(SceneView sv) {
        if(Event.current.type != EventType.Layout)
            return;
        if(!Camera.main)
            return;
        // Get a list of everything on the main camera that should be synced.
        SceneViewFilter[] cameraFilters = Camera.main.GetComponents<SceneViewFilter>();
        SceneViewFilter[] sceneFilters = sv.camera.GetComponents<SceneViewFilter>();

        // Let's see if the lists are different lengths or something like that. 
        // If so, we simply destroy all scene filters and recreate from maincame
        if(cameraFilters.Length != sceneFilters.Length) {
            Recreate(sv);
            return;
        }
        for(int i = 0; i < cameraFilters.Length; i++) {
            if(cameraFilters[i].GetType() != sceneFilters[i].GetType()) {
                Recreate(sv);
                return;
            }
        }

        // Ok, WHICH filters, or their order hasn't changed.
        // Let's copy all settings for any filter that has changed.
        for(int i = 0; i < cameraFilters.Length; i++)
            if(cameraFilters[i].hasChanged || sceneFilters[i].enabled != cameraFilters[i].enabled) {
                EditorUtility.CopySerialized(cameraFilters[i], sceneFilters[i]);
                cameraFilters[i].hasChanged = false;
            }
    }

    static void Recreate(SceneView sv) {
        SceneViewFilter filter;
        while(filter = sv.camera.GetComponent<SceneViewFilter>())
            DestroyImmediate(filter);

        foreach(SceneViewFilter f in Camera.main.GetComponents<SceneViewFilter>()) {
            SceneViewFilter newFilter = sv.camera.gameObject.AddComponent(f.GetType()) as SceneViewFilter;
            EditorUtility.CopySerialized(f, newFilter);
        }
    }
#endif
}