Victor wants to CREATE!

[John]

When the light is too diffuse it's really hard to capture the values and colors correctly, and the hue shifts and values are soooo subtle.

Dude, I hear you.

If you're not so much of a purist, you can try slapping a curve Adjustment layer (assuming you're working on PS) on the original photo, make the darkest values darker if the model is too light, or make the lightest lighter if otherwise.

Sometimes when the values are hardly shifting, it's hard to capture the form!

And man. Your portrait wasn't *that* bad!