I have a dance studio recital and will be setting up for individual and group portraits. High key on a white vinyl sweep. I'm lighting the BG with two in white umbrellas, and a two light set up for the subject, I usually go with a 3-1 ratio key to fill. Was thinking f/11 on the BG and f/8 on the key. Does a 3-1 work on High key, or is 2 or even 1-1 a better option. This will be a typical line em up and shoot em type setup, all different costumes, just trying to keep a good consistent look to the set up. We're going with 60 " white umbrellas in bounce for the key and fill since I can't afford a bigger softbox. I have a 48" octobox but have to back it up a bit for full length and lose some of the softness, so will stick with the 60's and keep it simple. Is a two stop difference between subject and BG too much?