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One head, Different lightning examples. Helpful for artists.

lighting reference Also, compile photos of friends/family as personal reference for structure/color/texture (this is really scary but probably helpful too so yeah)

luz+e+sombra+rosto.jpg (1173×1600)

An sculptural interpretation of the planar head affected by various directions of light. Note how the light effect directly correlate with the planes of the sculpture. Drawing a cube is like drawing a head.

Nice lighting reference on the hands. Shows light shining through as well as shadow. - The Art Resource

Nice lighting reference on the hands. Shows light shining through as well as shadow. - The Art Resource Hände zeichnen Hand-Positionen

Men's Hairstyles Hairflips

Drawing Portraits - Mens Hairstyles Hairflips - Discover The Secrets Of Drawing Realistic Pencil Portraits.Let Me Show You How You Too Can Draw Realistic Pencil Portraits With My Truly Step-by-Step Guide.

facial features  ILLUSTRATIONTIPS 3 top tips for mastering facial shadows

3 top tips for mastering facial shadows

Truck driver expressions, Chris Rawlinson on ArtStation at http://www.artstation.com/artwork/truck-driver-expressions

Truck driver expressions, Chris Rawlinson on ArtStation at http://www.artstation.com/artwork/truck-driver-expressions

「簡単な頭のうしろの描き方」/「犬牙あなほる」のイラスト [pixiv]

Kind of cheap, but clever. << This person just gave you an EASIER way to draw a back view of the head, at least be grateful you God forsaken bitch.