Tham khảo tài liệu 'hướng dẫn vẽ màu nước - phần 10', văn hoá - nghệ thuật, điêu khắc - hội họa phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | CHAPTER IO Seeing the Effects of Light Color Constancy and Simultaneous Contrast A given visual phenomenon may not be perceived at all unless it is actively looked for. Burnam Hanes and Bartleson quoted in Rossotti Colour Why the World Isn t Grey o understand the three-dimensionality of forms we see and use lights and shadows. These perceptions however are at an unconscious rather than a conscious level. We may see and consciously register for example that a man is wearing a light blue shirt but we are not consciously aware that light falling on the shirt causes changes in the shirt s color making it appear lighter on the highlighted folds and darker in the shadows of folds. We are also largely unaware that we are using the distribution of those lighted and shadowed areas to know the three-dimensional shape of the body beneath the shirt Figure io-i . In learning to draw and in learning to use color these perceptions rise to the conscious level we sec the shapes of lights and shadows we see the color changes that light causes and we become aware of how important these changes are to our comprehension of the shapes of things in I 12 Color by Betty Edwards Fig. 10-1. The strong lights and shadows of the children s clothing define the underlying volumes of their bodies. Edward Potthast 1857-1927 Beach Scene c. 1916 20 oil on canvas 61 x cm 24 x 30 in. . Hirshhorn Museum and Sculpture Garden Smithsonian Institution Gift of Joseph H. Hirshhorn 1966 photograph by Lee Stalsworth. our world. This awareness opens up new levels of perception and appreciation of light and color. For many people learning to see how light affects color is a revelation similar to seeing the after-images phenomenon for the first time. The Next Step Seeing How Light Affects the Colors of Three-Dimensional Shapes Thus far you have learned the basics of color by working with colors as they appear in two-dimensional colored patterns. The challenging next step is learning to see how light affects
