Thanks for all the advice. I'm still using some old 2008 IBL's, so bought a simple new one from a big name vendor here at Rendo published in 2014; result was subtly different, skin a bit shinier, but the darkness of the stock C6 mat didn't change. At the moment the only light set I have with a dome is an outdoor set, and scenes (even Callie 6's skin) look bright - as if outdoor. I should probably follow up on WandW's suggestion though.

However, I did get the Yannek's "Fusion Skin Texture for Callie 6" from DAZ, which shows a disproportionate difference. Given the promo text for "Fusion" is little more than "Hey, here's another skin for Callie 6 you can buy", I wonder if it was actually made for use in Poser?

• Upper left: DAZ 3D's promo for Callie 6

• Lower left: DAZ 3D's promo for Fusion Skins

• Upper right: Callie 6 in PoserPRO 2014

• Lower right: C6 Fusion skin in PoserPRO 2014

I guess (to me) this clearly shows how the skin is bundled matters. In DS, the Fusion skin almost looks a little darker than the base skin, yet is much lighter in Poser. I'll eventually get the "Victoria 4 for Genesis 2 Female" module, but DAZ (so far) is not discounting.