Julie,
but that's the fun of it . I don't know, maybe it's just me but I set up my studio lights in 50 or 60 different places every year and I've never had a major problem with it. I always use umbrellas for bounce and I always set the lights up the same way: 45 degrees to the subject. And I calibrate exposure with a flash meter.

Regardless of where I shoot, it's always F8 or F9 at 1/200 sec. If the area I set up is reflective, I move the lights farther back; if it's absorbtive, I move them closer. I like it because I'm always shooting at my lens' sweet spot and the lighting is always the same in terms of color.

For me, the ring-to-ring shooting with the 580 on the camera and different subject to camera distances is more difficult not in terms of the exposure but in terms of back-end processing. Each image requires slightly different adjustments for fleshtones and color balance.

Give me a studio set-up any time.

Jim