   defaultQ: 1
   defaultScales: [0.4, 0.6, 1.7]
   
+  
   events:
-    'next' : 'nextPage getNextSubject'
-    'prev' : 'prevPage getNextSubject'
-    'setting:alpha' : 'updateAlpha'
-    'setting:q' : 'updateQ'
-    'setting:scale' : 'updateScale'
-    'setting:extent' : 'updateExtent'
+    'next'            : 'nextPage getNextSubject'
+    'prev'            : 'prevPage getNextSubject'
+    'setting:alpha'   : 'updateAlpha'
+    'setting:q'       : 'updateQ'
+    'setting:scales'  : 'updateScale'
+    'setting:extent'  : 'updateExtent'
+  
   
   constructor: (selector) ->
     _.extend @, Ubret.Sequential

    @on 'data', @requestChannels
  
  # Request the appropriate WebFITS API (WebGL or Canvas)
  getApi: =>
    unless DataView?
      alert 'Sorry, your browser does not support features needed for this tool.'
    
    # Determine if WebGL is supported, otherwise fall back to canvas
    canvas  = document.createElement('canvas')
    context = canvas.getContext('webgl')
    context = canvas.getContext('experimental-webgl') unless context?

    # Load appropriate WebFITS library asynchronously
    lib = if context? then 'gl' else 'canvas'
    url = "javascripts/webfits-#{lib}.js"
    $.getScript(url, =>
      @dfs.webfits.resolve()

    @wfits?.setQ(@opts.q)
    
  updateScale: =>
    @wfits?.setScales.apply(@wfits, @opts.scales)
  
  updateStretch: =>
    @stretch = @opts.stretch
