Not really sure how to define the "soft moonlight" look I am thinking about. I have studied moonlight a decent amount, and, depending on the clouds and phase, it can be soft or hard, just like sunlight (just not as hard on the hard end).
I really like the Profoto Magnum reflector and the light it produces, however, for this project, that is too hard. I am looking for something softer and larger, but not diffused like a soft box or octa bank.
If I can get access, I would plan on shooting this about 40 minutes after dusk, using the last remanents of sunlight as fill, along with a 30'' lantern boomed above set (and several other lights in the restaurant and a couple of models and other things).
I am not too concerned with power, since these would be shot at ISO 200 or 400, and fairly wide open at that. I have more then enough power to get the job done.
However, what I am concerned about is shadow edge quality, which is why I initially felt a white parabolic would be best. I tested out my silver umbrellas yesterday and the shadows are not so great. (They are also cheap umbrellas, and I would be rent a better one.)
Does a silver parabolic produce better shadows? How about a silver with a white sock (diffusion) over the umbrella; is that stronger or softer then using just a white parabolic?
Attached is an image I use the Magnum reflector as my main key light (coming in through a window on the right). This is a look I would like to produce, only softer (and bluer, but I got that handled).