diff --git a/src/iiiftilesource.js b/src/iiiftilesource.js
index ae1896df..9c0ea902 100644
--- a/src/iiiftilesource.js
+++ b/src/iiiftilesource.js
@@ -65,10 +65,19 @@ $.IIIFTileSource = function( options ){
     //      to preserve backward compatibility.
     options.tileSize = this.tile_width;
 
-    options.maxLevel = options.maxLevel ? options.maxLevel : Number(
-        Math.ceil( Math.log( Math.max( this.width, this.height ), 2 ) )
-    );
-
+    if (! options.maxLevel ) {
+      var mf = -1;
+      if ( this.scale_factor instanceof Array ) 
+        for ( var i = 0; i < this.scale_factor.length; i++ )
+        {
+            var cf = Number( this.scale_factor[i] );
+            if ( !isNaN( cf ) && cf > mf ) mf = cf;
+        }
+      if ( mf < 0 ) 
+         options.maxLevel = Number( Math.ceil( Math.log( Math.max( this.width, this.height ), 2 )))
+      else options.maxLevel = mf;
+    }
+    
     $.TileSource.apply( this, [ options ] );
 };
 
@@ -176,7 +185,7 @@ $.extend( $.IIIFTileSource.prototype, $.TileSource.prototype, {
             iiif_tile_h;
 
 
-        if ( level_width < this.tile_width || level_height < this.tile_height ){
+        if ( level_width < this.tile_width && level_height < this.tile_height ){
             iiif_region = 'full';
         } else {
             iiif_tile_x = x * iiif_tile_size_width;