So I bought two new umbrellas recently. The one here is white, the other is a silver interior. They're described as 7 foot size. Which means in real life the actual diameter across the front is a couple inches less than six feet. The seven foot figure comes from measuring across the curvature of the back of the umbrella! Sort of like a 2x4 piece of lumber, I guess.
My test today was to get an idea how it'll work for a single-person portrait. In one way it's overkill, but if the result is worth it, then it's OK. I can already tell I wouldn't use it indoors with low ceilings. In such a situation the umbrella would be so low it would illuminate the person's nostrils.