盼星星盼月亮，终于盼到了上课:)
课刚刚开始，同学们就兴奋得拿出自己的照片，让老师评论。有的人居然拿出20多张照
片，让老师挑。等到轮到我的时候，课时已经过半。我挑出5张自己的照片给老师评价
。老师看到我的照片基本上都是Macro的主题，建议我参加她的另外一门课’
Introduction to Macro Nature Photography’。
等老师真正开始讲课的时候，已经是开课1个半小时之后了。这堂课的主题是景深(
Depth of Filed).
1.什么是DOF?
DOF is the area of acceptable sharpness in front of and behind the point of
focus. DOF is generally referred to in terms of being shallow or deep. This
area of sharpness extends 1/3 in front of the poiit of focus and 2/3 behind
the point of focus. (所以在拍风景照片时,
