| 1. | A typical lens has a focal length(f)of 625 mm .
常见镜头的焦距（f）为625毫米。 |
| 2. | As a result, the focal lengths in these planes will be different .
结果，这两个平面内的焦距将不同。 |
| 3. | The focal length of a given lens is different for different colors .
一个特定的透镜的焦距因颜色的不同而不同。 |
| 4. | In camera, the lens must be focused on the object to be photographed .
照相机内的镜头必须对准要拍照的物体调节焦距。 |
| 5. | The focal length of the camera lens plays an important role in photo criteria .
摄影机镜头的焦距在摄影规范中起着重要的作用。 |
| 6. | The unsteadiness of air becomes prohibitive only if instruments with large focal length are used .
只有在使用长焦距的仪器时，才不允许空气的不稳定。 |
| 7. | The wearer of such glasses could change the focus by sliding a switch along one arm of the frame .
带这种眼镜的人通过调整一只眼镜腿上的滑动开关可以改变焦距。 |
| 8. | The focal length of the conelensing lens should be such that the image of the source just fills the projecting lens .
聚光透镜的焦距应使光源的像正好照满放映透镜。 |
| 9. | Spot diameters of just a few thousands of an inch can readily be attained with convenient short focal length lenses .
用普通的短焦距透镜不难得到直径只有几十微米的光点。 |
| 10. | He took out the binoculars and adjusted the focus
他取出双筒望远镜并调整了焦距。 |
