To see progress messages when rendering, set Verbosity Level to Progress messages in Render > Render Current Frame > or Render > Batch Render >.
Select Window > Rendering Editors > Render Settingsor click the Render Settings window icon.
Caustics (in the Rendering Features section of the Features tab) is automatically enabled.
If the default settings are not sufficient to achieve the look you want (or to reduce render speed), tweak the caustics settings until you achieve the look you want. See Caustics and Global Illumination for more information.