unityboxer, you're nearly there with your scene. Make the ambient level for the ground and ball much darker (I use the colour picker rather than the slider as it gives more control). To compensate for the darkness, you need more light. Select your ambient-light-source-surface and set reflection and transparency to 100 (as well as max ambience). This will increase the render times. You can also replicate the ambient-light-source-surface and stack them (I think you have to move each one slightly off axis from the rest, and this might not work with the reflection set to max (no time to fiddle at the moment). But hey, you can already see the caustics in yours as it is.