| Orion Short-Tube 80 (80mm) Refractor 400mmFL @f/5.0 |
| Design | Focal Length (mm) |
Apparent Field (°) |
Barrel Size |
Mag. (x) |
Exit Pupil (mm) |
True Field (°) |
True Field @1000 yards (feet) |
Mag.
w/2x Barlow |
Mag.
w/2x Big Barlow or Powermate |
Mag. w/2.5x Powermate |
Mag. w/3x Barlow |
Mag. w/4x Powermate |
Mag. w/5x Powermate |
| Plössl | 55 | 50 | 2" | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Plössl | 40 | 43 | 1¼" | 10.0 | 8.0 | 3.9 | 202.5 | 20.0 | 20.0 | 25.0 | 30.0 | 40.0 | 50.0 |
| Plössl | 32 | 50 | 1¼" | 12.5 | 6.4 | 3.9 | 202.5 | 25.0 | 25.0 | 31.3 | 37.5 | 50.0 | 62.5 |
| Plössl | 25 | 50 | 1¼" | 16.0 | 5.0 | 3.0 | 159.0 | 32.0 | 32.0 | 40.0 | 48.0 | 64.0 | 80.0 |
| Plössl | 20 | 50 | 1¼" | 20.0 | 4.0 | 2.4 | 128.3 | 40.0 | 40.0 | 50.0 | 60.0 | 80.0 | 100.0 |
| Plössl | 15 | 50 | 1¼" | 26.7 | 3.0 | 1.8 | 94.5 | 53.3 | 53.3 | 66.7 | 80.0 | 106.7 | 133.3 |
| Plössl | 11 | 50 | 1¼" | 36.4 | 2.2 | 1.3 | 68.3 | 72.7 | 72.7 | 90.9 | 109.1 | 145.5 | 181.8 |
| Plössl | 8 | 50 | 1¼" | 50.0 | 1.6 | 0.9 | 48.8 | 100.0 | 100.0 | 125.0 | 150.0 | 200.0 | 250.0 |
| Radian | 18 | 60 | 1¼" | 22.2 | 3.6 | 2.6 | 137.3 | 44.4 | 44.4 | 55.6 | 66.7 | 88.9 | 111.1 |
| Radian | 14 | 60 | 1¼" | 28.6 | 2.8 | 2.1 | 108.0 | 57.1 | 57.1 | 71.4 | 85.7 | 114.3 | 142.9 |
| Radian | 12 | 60 | 1¼" | 33.3 | 2.4 | 1.8 | 94.5 | 66.7 | 66.7 | 83.3 | 100.0 | 133.3 | 166.7 |
| Radian | 10 | 60 | 1¼" | 40.0 | 2.0 | 1.5 | 78.8 | 80.0 | 80.0 | 100.0 | 120.0 | 160.0 | 200.0 |
| Radian | 8 | 60 | 1¼" | 50.0 | 1.6 | 1.2 | 62.3 | 100.0 | 100.0 | 125.0 | 150.0 | 200.0 | 250.0 |
| Radian | 6 | 60 | 1¼" | 66.7 | 1.2 | 0.9 | 47.3 | 133.3 | 133.3 | 166.7 | 200.0 | 266.7 | 333.3 |
| Radian | 5 | 60 | 1¼" | 80.0 | 1.0 | 0.8 | 39.8 | 160.0 | 160.0 | 200.0 | 240.0 | 320.0 | 400.0 |
| Radian | 4 | 60 | 1¼" | 100.0 | 0.8 | 0.6 | 31.5 | 200.0 | 200.0 | 250.0 | 300.0 | 400.0 | 500.0 |
| Radian | 3 | 60 | 1¼" | 133.3 | 0.6 | 0.5 | 24.8 | 266.7 | 266.7 | 333.3 | 400.0 | 533.3 | 666.7 |
| Panoptic | 41 | 68 | 2" | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Panoptic | 35 | 68 | 2" | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Panoptic | 27 | 68 | 2" | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Panoptic | 24 | 68 | 1¼" | 16.7 | 4.8 | 3.9 | 202.5 | 33.3 | 33.3 | 41.7 | 50.0 | 66.7 | 83.3 |
| Panoptic | 22 | 68 | 2" & 1¼" | 18.2 | 4.4 | 3.6 | 187.5 | 36.4 | 36.4 | 45.5 | 54.5 | 72.7 | 90.9 |
| Panoptic | 19 | 68 | 1¼" | 21.1 | 3.8 | 3.1 | 159.8 | 42.1 | 42.1 | 52.6 | 63.2 | 84.2 | 105.3 |
| Panoptic | 15 | 68 | 1¼" | 26.7 | 3.0 | 2.4 | 128.3 | 53.3 | 53.3 | 66.7 | 80.0 | 106.7 | 133.3 |
| Nagler 5 | 31 | 82 | 2" | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Nagler 5 | 26 | 82 | 2" | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Nagler 4 | 22 | 82 | 2" | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Nagler 5 | 20 | 82 | 2" | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Nagler 4 | 17 | 82 | 2" | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Nagler 5 | 16 | 82 | 1¼" | 25.0 | 3.2 | 3.2 | 165.8 | 50.0 | 50.0 | 62.5 | 75.0 | 100.0 | 125.0 |
| Nagler 6 | 13 | 82 | 1¼" | 30.8 | 2.6 | 2.5 | 132.0 | 61.5 | 61.5 | 76.9 | 92.3 | 123.1 | 153.8 |
| Nagler 4 | 12 | 82 | 2" & 1¼" | 33.3 | 2.4 | 2.4 | 128.3 | 66.7 | 66.7 | 83.3 | 100.0 | 133.3 | 166.7 |
| Nagler 6 | 11 | 82 | 1¼" | 36.4 | 2.2 | 2.1 | 111.8 | 72.7 | 72.7 | 90.9 | 109.1 | 145.5 | 181.8 |
| Nagler 6 | 9 | 82 | 1¼" | 44.4 | 1.8 | 1.8 | 93.0 | 88.9 | 88.9 | 111.1 | 133.3 | 177.8 | 222.2 |
| Nagler 6 | 7 | 82 | 1¼" | 57.1 | 1.4 | 1.4 | 72.8 | 114.3 | 114.3 | 142.9 | 171.4 | 228.6 | 285.7 |
| Nagler 6 | 5 | 82 | 1¼" | 80.0 | 1.0 | 1.0 | 52.5 | 160.0 | 160.0 | 200.0 | 240.0 | 320.0 | 400.0 |
| Nagler | 4.8 | 82 | 1¼" | 83.3 | 1.0 | 0.9 | 49.5 | 166.7 | 166.7 | 208.3 | 250.0 | 333.3 | 416.7 |
| Nagler 6 | 3.5 | 82 | 1¼" | 114.3 | 0.7 | 0.7 | 36.0 | 228.6 | 228.6 | 285.7 | 342.9 | 457.1 | 571.4 |
| Nagler 6 | 2.5 | 82 | 1¼" | 160.0 | 0.5 | 0.5 | 25.5 | 320.0 | 320.0 | 400.0 | 480.0 | 640.0 | 800.0 |
| Nagler | 7 | 82 | 1¼" | 57.1 | 1.4 | 1.3 | 70.5 | 114.3 | 114.3 | 142.9 | 171.4 | 228.6 | 285.7 |
| Nagler Zoom | 2 - 4 | 50 | 1¼" | 200.0 - 100.0 | 0.4 - 0.8 | 0.2 - 0.5 | 12.8 - 24.8 | 400.0 - 200.0 | 400.0 - 200.0 | 500.0 - 250.0 | 600.0 - 300.0 | 800.0 - 400.0 | 1,000.0 - 500.0 |
| Nagler Zoom | 3 - 6 | 50 | 1¼" | 133.3 - 66.7 | 0.6 - 1.2 | 0.4 - 0.7 | 19.5 - 38.3 | 266.7 - 133.3 | 266.7 - 133.3 | 333.3 - 166.7 | 400.0 - 200.0 | 533.3 - 266.7 | 666.7 - 333.3 |
| Click Stop Zoom | 8 - 24 | 55 - 40 | 1¼" | 50.0 - 16.7 | 1.6 - 4.8 | 1.1 - 2.4 | 57.0 - 125.3 | 100.0 - 33.3 | 100.0 - 33.3 | 125.0 - 41.7 | 150.0 - 50.0 | 200.0 - 66.7 | 250.0 - 83.3 |