Translating is important to understand if you want to paint in a representational style. Translating is more than just converting what you see in the real world into two dimensional shapes, its also important to key the painting in a number of ways. Keying a painting is part of translating what you see. It is what we really do when we paint and especially when we paint from life.
Pigment can’t get the real amount of saturation or values of light and darks of nature. An artist has to paint the relationshipsof what they see, editing them down to fit into the ranges available to the limited properties of their colors. Artists have to key a limited set of paints to represent everything from white equals the orb of the sun to black equals the shadow under a rock in pigments. The same limitations apply to all aspects of the image drawing, color and every aspect of the scene in general- contrast, edge quality, details.
I. Levitan, D. Bunker, H.Von Zugel, I. Shishkin, H. Herzog