First post here, so I'm nervous... For half a year or so I am shooting 5x4. So far test shots and learning, I am mainly using it for portraits. With the end of summer in sight (I'm in the Netherlands), I am looking for more light. Most of my photography is daylight based and I am leaning towards continuous light. I am wondering if someone can point me in the directions of power needed for - mainly - head shots. I found the Calumet Quattro lights (they claim to be about 800W compared to traditional). From what I understood from "The Web", continuous light needs a lot more power than flashes. Any thoughts on these, or other recommendations? The goal is to shoot ISO100 film at about f/16 with a reasonable shutter time.