它提供了更广泛的角度捕捉以及高倍率变焦，逐步改变了对图像传感器的图像采集区。
It provides wider Angle capture as well as higher magnification zoom, by progressively changing the image capture area on the image sensor.
这种变焦距物镜有两个优点，一是可以实现高倍率变焦，二是容易消除在变焦过程中产生的像点移动现象。
Firstly, the zoom ratio may be enlarged. Secondly, the image point movement may be easily eliminated. The principle of optical compensated step zoom lens is explained.
应用推荐