CTIO 4m Telescope
Maximum recommended above pole positions
| Declination | Hour Angle | Airmass |
| -85 | 6:00 | 1.99 |
| -80 | 6:00 | 2.02 |
| -75 | 6:00 | 2.05 |
| -70 | 6:00 | 2.11 |
| -65 | 6:00 | 2.19 |
| -60 | 6:00 | 2.29 |
| -55 | 6:00 | 2.42 |
| -50 | 6:00 | 2.58 |
| -45 | 6:00 | 2.80 |
| -40 | 6:00 | 3.07 |
| -35 | 5:48 | 3.05 |
| -30 | 5:42 | 3.20 |
| -25 | 5:30 | 3.15 |
| -20 | 5:18 | 3.10 |
| -15 | 5:06 | 3.05 |
| -10 | 4:54 | 3.02 |
| -5 | 4:48 | 3.20 |
| 0 | 4:36 | 3.20 |
| 5 | 4:18 | 3.06 |
| 10 | 4:06 | 3.11 |
| 15 | 3:48 | 3.06 |
| 20 | 3:30 | 3.08 |
| 25 | 3:12 | 3.18 |
| 30 | 2:42 | 3.12 |