Quote - I am using a single sun/sky in a render, and the skin comes out looking strange.

Try this with a camera, even a camera phone. At midday ask a friend to stay in full sun light and take a photo. You will see how hard is to make people look good in that light. Try it for fun. Thensin is a harsh light with very high contrast that is not very flattering. 

The same is in Lux.

Paolo

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