Here's the scene, external download since file size too big for the forum:
http://www.mswee.net/xchange/220707_Water_Droplets_OBJ_FBX.zipDetails:
- export as OBJ and FBX (FBX keeps scene layers, local pivots and transforms, plus it attempts to keep materials, although many 3dsmax specific maps will not convert correctly, so just make your own)
- since the camera doesn't export, there's a Camera Object and a Camera_Target, use these to position and align your camera correctly
- Camera and Lights have the most important parameter values in their name (radius, intensity, directionality for the lights, for example)
- I've used cm as scene units, probably best to keep it that way
- included the texture used on the lights for a nicer falloff in the reflections
- included two CXR files for 2 of the renders I posted so you can see the post settings from Corona
- water material - refraction on at 1.0, IOR at 1.33
- caustic settings at defaults, only 'photons per iteration' increased to 8500
- Light 01 and 02 were used for the green surface render, Light 03 was used for the metallic surface render, in case you want to get the exact same results
Let me know if you need anything else.
Once you have set it all up and it renders like my green surface example, do a render with only Light 03 instead of Light 01+02 and observe how, suddenly, the water looks flat - similar to your initial setup where you were missing nice looking caustics. That's why trying to reproduce reference images closely is really important, as is the lighting setup to get nice looking results.