diff --git a/src/ol/source/zoomifysource.js b/src/ol/source/zoomifysource.js
index e798889f9a..60b2fe97eb 100644
--- a/src/ol/source/zoomifysource.js
+++ b/src/ol/source/zoomifysource.js
@@ -13,60 +13,22 @@ goog.require('ol.tilegrid.Zoomify');
 /**
  * @constructor
  * @extends {ol.source.TileImage}
- * @param {olx.source.ZoomifyOptions} options Zoomify options.
+ * @param {olx.source.ZoomifyOptions=} opt_options Options.
  * @todo stability experimental
  */
-ol.source.Zoomify = function(options) {
+ol.source.Zoomify = function(opt_options) {
 
-  /**
-   * Prefix of URL template.
-   * @private
-   * @type {!string}
-   */
-  this.url_ = options.url;
+  var options = goog.isDef(opt_options) ? opt_options : {};
 
-  /**
-   * Size of the image.
-   * @private
-   * @type {ol.Size}
-   */
-  this.size_ = options.size;
+  var size = options.size;
 
-  /**
-   * Depth of the Zoomify pyramid, number of tiers (zoom levels).
-   * @private
-   * @type {number}
-   */
-  this.numberOfTiers_ = 0;
-
-  /**
-   * Number of tiles up to the given tier of pyramid.
-   * @private
-   * @type {Array.<number>}
-   */
-  this.tileCountUpToTier_ = null;
-
-  /**
-   * Size (in tiles) for each tier of pyramid.
-   * @private
-   * @type {Array.<ol.Size>}
-   */
-  this.tierSizeInTiles_ = null;
-
-  /**
-   * Image size in pixels for each pyramid tier.
-   * @private
-   * @type {Array.<ol.Size>}
-   */
-  this.tierImageSize_ = null;
-
-  var imageSize = [].concat(this.size_);
+  var imageSize = size.slice();
   var tiles = [
-    Math.ceil(this.size_[0] / ol.DEFAULT_TILE_SIZE),
-    Math.ceil(this.size_[1] / ol.DEFAULT_TILE_SIZE)
+    Math.ceil(imageSize[0] / ol.DEFAULT_TILE_SIZE),
+    Math.ceil(imageSize[1] / ol.DEFAULT_TILE_SIZE)
   ];
-  this.tierSizeInTiles_ = [tiles];
-  this.tierImageSize_ = [imageSize];
+  var tierSizeInTiles = [tiles];
+  var tierImageSize = [imageSize];
 
   while (imageSize[0] > ol.DEFAULT_TILE_SIZE ||
       imageSize[1] > ol.DEFAULT_TILE_SIZE) {
@@ -79,24 +41,24 @@ ol.source.Zoomify = function(options) {
       Math.ceil(imageSize[0] / ol.DEFAULT_TILE_SIZE),
       Math.ceil(imageSize[1] / ol.DEFAULT_TILE_SIZE)
     ];
-    this.tierSizeInTiles_.push(tiles);
-    this.tierImageSize_.push(imageSize);
+    tierSizeInTiles.push(tiles);
+    tierImageSize.push(imageSize);
   }
 
-  this.tierSizeInTiles_.reverse();
-  this.tierImageSize_.reverse();
-  this.numberOfTiers_ = this.tierSizeInTiles_.length;
+  tierSizeInTiles.reverse();
+  tierImageSize.reverse();
+  var numberOfTiers = tierSizeInTiles.length;
   var resolutions = [1];
-  this.tileCountUpToTier_ = [0];
-  for (var i = 1; i < this.numberOfTiers_; i++) {
+  var tileCountUpToTier = [0];
+  var i;
+  for (i = 1; i < numberOfTiers; i++) {
     resolutions.unshift(Math.pow(2, i));
-    this.tileCountUpToTier_.push(
-        this.tierSizeInTiles_[i - 1][0] * this.tierSizeInTiles_[i - 1][1] +
-        this.tileCountUpToTier_[i - 1]
+    tileCountUpToTier.push(
+        tierSizeInTiles[i - 1][0] * tierSizeInTiles[i - 1][1] +
+        tileCountUpToTier[i - 1]
     );
   }
 
-
   var createFromUrl = function(url) {
     var template = url + '{tileIndex}/{z}-{x}-{y}.jpg';
     return (
@@ -111,8 +73,8 @@ ol.source.Zoomify = function(options) {
             return undefined;
           } else {
             var tileIndex = tileCoord.x +
-                (tileCoord.y * this.tierSizeInTiles_[tileCoord.z][0]) +
-                this.tileCountUpToTier_[tileCoord.z];
+                (tileCoord.y * tierSizeInTiles[tileCoord.z][0]) +
+                tileCountUpToTier[tileCoord.z];
             return template.replace('{tileIndex}', 'TileGroup' +
                 Math.floor((tileIndex) / ol.DEFAULT_TILE_SIZE))
                            .replace('{z}', '' + tileCoord.z)
@@ -159,9 +121,8 @@ ol.source.Zoomify = function(options) {
     resolutions: resolutions
   });
   var tileUrlFunction = ol.TileUrlFunction.withTileCoordTransform(
-      tileGrid.createTileCoordTransform({extent: [0, 0].concat(this.size_)}),
-      createFromUrl(this.url_));
-
+      tileGrid.createTileCoordTransform({extent: [0, 0, size[0], size[1]]}),
+      createFromUrl(options.url));
 
   goog.base(this, {
     attributions: options.attributions,