| 1. | The primary mirror is 80 cm in diameter, a respectable size even for an observatory on the ground .
主镜的直径为80厘米，这一口径即使在地面天文台也是很可观的。 |
| 2. | Lens is used to bend light to a point , called the
作主镜，以收集及屈折光线到 |
| 3. | Step 3 : center your primary mirror ' s sweet spot in the eyepiece ' s field of view
把主镜的甜点调整到目镜视场中。 |
| 4. | The important thing to know that it has an axis of symmetry ? the optical axis
重点是知道主镜有一个对称轴? ?光轴。 |
| 5. | Progress on testing large aspheric mirror with annular subaperture method
以环形子孔径法检测大口径非球面主镜的研究进展 |
| 6. | Manufacturing of large aspherical primary mirror is one of the key technologies for optics
大口径非球面主镜的加工是光学制造里的关键技术之一。 |
| 7. | Most mirror cells have three adjustment screws or three pairs of push - pull adjustments
绝大多数的镜室（固定支撑主镜）有3个调整螺丝或3对推拉杆。 |
| 8. | This is best done during daylight , with the telescope aimed at the ceiling or the sky ( be careful to avoid the sun )
所以使目镜和主镜的像吻合是调校光轴的终极目标。 |
| 9. | Step 2 : here you adjust the tilt of the secondary mirror to aim the focuser ' s axis at the center of the primary
现在你已经调整了副镜的倾斜程度，把调焦座的中轴已经对准了主镜。 |
| 10. | As long as the pointing error is no more than 1 or 2 percent of the main mirror ' s diameter , it makes no visible difference
只要误差在主镜直径的百分之一或二以内，目视是觉察不到的。 |
