100% Pure IRAY render with 4700 iterations. No postwork
Model: Rebeca (Genesis 3 morph)
Camera:
Focal Length: 300 mm.
Focal Distance: 2.88 mts.
F/Stop: 90
Tone Mapping:
Burn Highlights: 0.1
Crush Blacks: 0.1
Saturation: 1.8
Gamma: 1.7
Bloom:
Bloom Filter Radius: 0.5
Bloom Filter Threshold: 80k
Bloom Filter Brightness Scale: 0.7
Spectral Rendering:
Spectral Conversion Intent: natural
Spectral Observer: cie1964
Lighting: 1 HDR environment + 1 spotlight
Colors used: 92470
Original Size: 1000x1500
Render time: 1 hour 14 minutes in Nvidia GTX970

https://www.deviantart.com/bestmanpi/art/Rebeca-Portrait-385-880292982