第一点就是被一些专业人士所熟知的“裁切系数”(crop factor，也称镜头焦距转换率)。

The first is what is known as the 'crop factor'.

youdao

只有配用1.5x或1.6x镜头焦距转换率的镜头，方能获得正常的广角效果，不过也不必担心什么，这些镜头已经随处可见，并且比起全画幅的要便宜不少。

With a crop factor of 1.5x or 1.6x you need special digital lenses to get true wideangle results, but these are readily available and are usually less expensive than their 'full frame' counterparts.

youdao

只有配用1.5x或1.6x镜头焦距转换率的镜头，方能获得正常的广角效果，不过也不必担心什么，这些镜头已经随处可见，并且比起全画幅的要便宜不少。

With a crop factor of 1.5x or 1.6x you need special digital lenses to get true wideangle results, but these are readily available and are usually less expensive than their 'full frame' counterparts.

youdao