     
     @wfits.setCalibrations(1, 1, 1)
     @wfits.setScales.apply(@wfits, @defaultScales)
-    @wfits.setAlpha(@defaultAlpha)
-    @wfits.setQ(@defaultQ)
+    @wfits.setAlpha(@opts.alpha or @defaultAlpha)
+    @wfits.setQ(@opts.q or @defaultQ)
+    
+    # Enable mouse controls
+    @wfits.setupControls({
+      onmousemove: (e) =>
+        @settings({
+          xOffset: @wfits.getXOffset()
+          yOffset: @wfits.getYOffset()
+        })
+    })
     
     # Default to color composite
     @wfits.drawColor('i', 'r', 'g')
-    
-    # Enable mouse controls
-    @wfits.setupControls()
-    
-    @trigger 'swviewer:loaded'
   
   start: =>
     console.log 'start'

      @wfits.setStretch(@stretch)
  
  updateAlpha: =>
    @wfits.setAlpha(@opts.alpha)
    
  updateQ: =>
    @wfits.setQ(@opts.q)
    
  updateScale: =>
    band = @opts.scale.band

  
  # Initialize a WebFITS object
  initWebFITS: =>
    @wfits?.teardown()
    
    @wfits = new astro.WebFITS(@el, @dimension)
    
    unless @wfits.ctx?
      alert 'Something went wrong initializing the context'
    
    # Load offsets if they exists
    @wfits.xOffset = @opts.xOffset or @wfits.xOffset
    @wfits.yOffset = @opts.yOffset or @wfits.yOffset
  
  # Call when all FITS received and WebFITS library is received
  allChannelsReceived: (e) =>
