Ben Goren wrote: ::snip? SNIP!::
As for paper white in camera profiles...yeah, I know all about that. That's why I've worked out a setup with four strobes at 45-degree angles surrounding something to be copied. Falloff (``vignetting'') from the lens can still be a problem, but it's minimal enough to not worry about on a decent stopped-down macro lens.
Err... four strobes? That seems like serious overkill. How far is the target from your lens, and what focal length and exposure settings are you using? I would expect a single strobe shooting directly at the target to be able to illuminate it properly and without any noticeable fall-off — unless you're using a giant target, the flash's hotspot should be able to cover it easily.