焦距是什么?在摄影中有什么作用?

2025-03-16 05:54:44
推荐回答(2个)
回答1:

在摄影中,什么是焦距?

回答2:

从百度百科复制过来的,或者你自己往看看:焦距,是光学系统中衡量光的聚集或发散的度量方式,指从透镜的光心到光聚集之焦点的间隔。亦是照相机中,从镜片中心到底片或CCD等成像平面的间隔。具有短焦距的光学系统比长焦距的光学系统有更佳聚集光的能力。简单的说焦距是焦点到面镜的顶点之间的间隔。 焦距有什么用?焦距是镜头所具备的属性。“有什么用”这样的说法是不正确的。比如说,一个文件的大小是256KB,这是它的属性,你说他的大小有什么用?对于相同画幅来说,排除鱼眼镜头,镜头的焦距越大,对角线视角越小。其它不变的情况下,焦距越大,景深越浅。假如同样是f/2.8的镜头,一个400mm的镜头的通光孔一定比一个40mm的镜头大得多。

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