Meade Instruments Corporation - Meade LX200 Instruction Manuals
diameter is reduced, the minimum practical power with the 8" LX200 is increased to about 60X, to about 75X with the 10" LX200 and to about 90X with the 12" LX200; powers lower than this level should be avoided during daytime observations. A reasonable magnification range for daytime terrestrial observations through the 7" LX200 is from about 70X to 180X; 8" LX200 is from about 80X to 190X; through the 10" LX200 from about 100X to 200X, the 12" LX200 from 120X to 240X. It should be noted, however, that the higher magnifications may not be used due to severe air turbulence near the ground.
Accessories are available both to increase and decrease the operating eyepiece power of the telescope. See your Meade dealer and the latest Meade Telescope Systems and Accessories Catalog for information on accessories.
[ toc ] 2. Apparent Field and Actual Field
Two terms that are often confused and misunderstood are "Apparent Field" and "Actual Field". "Apparent Field" is a function of the eyepiece design and is built into the eyepiece. While not totally accurate (but a very good approximation), "Apparent Field" is usually thought of as the angle your eye sees when looking through an eyepiece. "Actual Field" is the amount of the sky that you actually see and is a function of the eyepiece being used and the telescope.
The "Actual Field" of a telescope with a given eyepiece is calculated by dividing the "Apparent Field" of the eyepiece by the power obtained using that eyepiece.
The following table lists the most common optional eyepieces available and the "Apparent Field" for each eyepiece. The power and "Actual Field" of view that each eyepiece yields is listed for each basic telescope optical design.
| 7" f/15 | 8" f/6.3 | 10" f/6.3 | 8"f/l 0 | 10" f/10 | 12" f/10 |
Eyepiece/Apparent Field | Power/ | Power/ | Power/ | Power/ | Power/ | Power/ |
| Actual Fiield | Actual Field | Actual Field | Actual Field | Actual Field | Actual Field |
Super Plössl Eyepieces
6.4mm/52° | 417/0.12° | 200/0.26° | 250/0.21 ° | 313/0.17° | 391/0.13° | 476/0.11° |
9.7mn/52° | 275/0.19° | 132/0.39° | 165/0.32° | 206/0.25° | 258/0.20° | 314/0.17° |
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12.4mn/52° | 215/0.24° | 103/0.50° | 129/0.40° | 161/0.32° | 202/0.26° | 246/0.21° |
15mn/52° | 178/0.29° | 85/0.61° | 107/0.49° | 133/0.39° | 167/0.31° | 203/0.26° |
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20mm/52° | 134/0.39° | 64/0.81 ° | 80/0.65° | 100/0.52° | 125/0.42° | 152/0.34° |
26mm/52° | 103/0.50° | 49/1.06° | 62/0.84° | 77/0.68° | 96/0.54° | 117/0.44° |
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32mm/52° | 83/0.63° | 40/1.30° | 50/1.04° | 63/0.83° | 78/0.67° | 95/0.55° |
40mn/44° | 67/0.66° | 32/1.69° | 40/1.35° | 50/0.88° | 63/0.70° | 76/0.53° |
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56mm/52° (2"O.D.) | 48/1.08° | 23/2.27° | 29/1.82° | 36/1.46° | 45/1.16° | 54/1.04° |
Super Wide Angle Eyepieces |
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13.8mm/67° | 193/0.35° | 93/0.72° | 116/0.58° | 145/0.46° | 181/0.37° | 221/0.30° |
1 Smm/67° | 148/0.45° | 71/0.94° | 89/0.75° | 111/0.60° | 139/0.48° | 169/0.40° |
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24.5mm/67° | 109/0.61° | 52/1.28° | 65/1.03° | 82/0.82° | 102/0.66° | 124/0.54° |
32mm/67° (2"O.D.) | 83/0.81° | 40/1.67° | 50/1.34° | 63/1.07° | 78/0.86° | 95/0.71° |
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40mm/67° (2"O.D.) | 67/1.00° | 32/2.09° | 40/1.67° | 50/1.34° | 63/1.07° | 76/0.88° |
Ultra Wide Angle Eyepleces |
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4.7mm/84° | 568/0.15° | 272/0.31° | 340/0.25° | 426/0.20° | 532/0.16° | 649/0.13° |
6.7mm/84° | 399/.021° | 191/0.44° | 239/0.35° | 299/0.28° | 373/0.23° | 455/0.18° |
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8.8mm/84° | 303/0.28° | 145/0.58° | 182/0.46° | 227/0.37° | 284/0.30° | 346/0.24° |
14mm/84° | 191/0.44° | 91/0.92° | 114/0.73° | 143/0.59° | 179/0.47° | 218/0.39° |
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