照片展示了直射阳光下的球体。它从亮部到暗部的调子泾渭分明。这个就是素描关系。
The photograph above shows a sphere in direct sunlight. It has a distinct set of tonal steps from light to shadow, known as modeling factors.
许：这两张照片的调子截然不同，一张给我以诡异、阴郁的感觉，另一张是春暖花开，晴空万里。
Xu: the tone of these two photographs are completely different, one makes me feel quirky and gloomy while the other brings the feeling of spring flowers and blue sky.
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