         @wfits.setStretch(@opts.stretch)
   
   updateAlpha: =>
-    @wfits?.setAlpha(@opts.alpha)
+    @wfits?.setAlpha(@opts.alpha) if @ready
     
   updateQ: =>
-    @wfits?.setQ(@opts.q)
+    @wfits?.setQ(@opts.q) if @ready
     
   updateScale: =>
-    @wfits?.setScales.apply(@wfits, @opts.scales)
+    @wfits?.setScales.apply(@wfits, @opts.scales) if @ready
   
   updateStretch: =>
     @stretch = @opts.stretch
-    @wfits?.setStretch(@stretch)
+    @wfits?.setStretch(@stretch) if @ready
 
   updateExtent: =>
-    @wfits?.setExtent(@opts.extent.min, @opts.extent.max)
+    @wfits?.setExtent(@opts.extent.min, @opts.extent.max) if @ready
 
 
 window.Ubret.SpacewarpViewer = SpacewarpViewer

  
  # Call when all FITS received and WebFITS library is received
  allChannelsReceived: (e) =>
    
    # Get extent for each layer and add to settings
    mins = @collection.map( (d) -> return d.get('minimum') )

    # Set parameters
    @stretch = 'linear'
    @collection = new Layers()
    @ready = false
    
    # Set various deferred objects to handle asynchronous requests.
    @dfs =
