| 1. | The Chinese Future Giant Telescope has a primary focal ratio of 1.2.
|
| 2. | :It's not the absolute diameter that matters, but the focal ratio or f-number.
|
| 3. | It uses a concave focal ratios, Dall-Kirkhams are seldom faster than f / 15.
|
| 4. | The particular aberrations associated with the coma ) are also worsened with short focal ratios.
|
| 5. | Also, for fast focal ratios, the curve obtained is not sufficiently exact and requires additional hand correction.
|
| 6. | Early off-axis designs such as the astigmatism and long focal ratios, which make them useless for research.
|
| 7. | The " focal length " of the telescope objective is the diameter of the objective times the focal ratio.
|
| 8. | Many of these targets are small and require long focal lengths, which can push the focal ratio far above 5.
|
| 9. | The focal length of 12.1 m combines with the baffled aperture of 3.7 m to a focal ratio of 3.26.
|
| 10. | A secondary mirror is to produce an unobstructed field-of-view of 20 arcminutes in diameter with a focal ratio of 15.
|
मोबाइल