| 1. | 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。 |
| 2. | 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。 |
| 3. | 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。 |
| 4. | 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。 |
| 5. | 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。 |
| 6. | 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。 |
| 7. | Photographic lenses - measurement for the focal length
摄影镜头.焦距测量 |
| 8. | Fundamental standards for optics - determination of focal length
光学基础标准.焦距测定 |
| 9. | Effect of temperature on measuring system of long focal length
温度对长焦距测量精度的影响 |
| 10. | Determine the focal length of your lens
决定你镜头的焦距。 |
