lens focal length

例句：

1. 1. The camera has a large lens that allows it to capture detailed images.
   这台相机有一个大透镜，可以捕捉到详细的图像。
2. 2. The scientist used a microscope to examine the sample through a small lens.
   科学家使用显微镜通过一个小透镜来检查样本。
3. 3. Lenses are essential for photography as they focus light onto the image sensor.
   透镜对于摄影来说是必不可少的，因为它们将光线聚焦到图像传感器上。