Iray Discussion: Lighting And Skin Tone

After DAZ declined a product if mine and Fuseling's, I went back to revisit its lighting and redo all the renders for it (and many of the skin settings; what I learned from that led to the Kasper tutorial). 

In the process I discovered that I had been overcompensating with glossy settings that were too high, because most of my test characters were pale.  There's a good reason why so many of the hyper-real renders you see have characters who look very tan and oily.  It's the same reason why bodybuilders almost always use tanner and oils on their skin for competitions: visual detail on skin and muscle is easiest to see on shiny mid-toned surfaces.

Skin that is very pale tends to reflect so much light that it's whited out on the highlights, making the character's details harder to see.  Skin that is very dark can actually absorb more light, so more light is needed to show off its highlights.

Now, I love extremes of color and tone on my rendered characters.  So when working with very light or dark skins:

Very pale:  Turn down the lights and use softer, more diffuse lighting (more, weaker lights).

Very dark: Turn up the lights and use harder, more direct lighting (fewer, brighter lights).

In neither case should you change the glossy settings.  Human skin isn't actually shinier or oilier when it's dark (some dark-skinned people are more susceptible to dry skin than the very pale!).  It's just that having a darker base color makes highlights more visible right up until you hit the "very dark" tipoff point where it becomes overly absorptive.

Because Iray is an unbiased engine, changing the gloss settings is no longer the best answer on adjusting for different skin tones as it was with DAZ Studio 3Delight.  Adjusting the lighting is a much more successful method - you can light an albino or an aboriginal Australian with the same skin settings as long as the lights are set properly.

Now, there may be situations where you need the overall scene itself to have a certain type of light, and in that case, it may be best to darken your pale people and lighten your dark people a bit; it can be a decent "quick fix" if you've already created your detailed space scene and are tearing your hair out over trying to light everyone.  So when in doubt, tan them.