Grab diffuse slider and move it to the right as long as you will get desired effect on the live preview,
maybe it would be something like:
Diffuse : 0.7
Transmissivity : 0.3
Diffuse : 0.9
Transmissivity : 0.1
I’ve been trying to get this type of effect as well. Playing with the settings as discussed in this thread only seems to change transparency. I need something translucent not transparent. Is this possible? If not can it be added as a feature request?