Leisure Time LX20 Apparent Field and Actual Field, Magnification and Field of View

Page 24

MAGNIFICATION AND FIELD OF VIEW

1. Magnification

2 4

bright, clearly resolved but smaller image will show far more detail than a dimmer, poorly resolved larger image.

The magnification (power) of the telescope depends on two characteristics: the focal length of the main telescope and the focal length of the eyepiece used during a particular observation. For example, the focal length of the LX200 7" f/15 telescope is fixed at 2670mm; the focal length of the 8" f/10 telescope is fixed at 2000mm; the focal length of the 10" f/10 telescope is fixed at 2500mm; and the focal length of the 12" f/10 telescope is fixed at 3048mm. To calculate the power in use with a particular eyepiece, divide the focal length of the eyepiece into the focal length of the main telescope.

Example: The power obtained with the 8" LX200 with the SP 26mm eyepiece is:

The type of eyepiece (whether MA "Modified Achromatic," PL "Plossl," SP "Super Plossl," etc.) has no bearing on magnifying power but does affect such optical characteristics as field of view, flatness of field and color correction.

The maximum practical magnification is determined by the nature of the object being observed and, most importantly, by the prevailing atmospheric conditions. Under very steady atmospheric "seeing," the 7" LX200 may be used at powers up to about 450X on astronomical objects, the 8" LX200 may be used at powers up to about 500X, the 10" LX200 up to about 600X, and the 12" LX200 up to about 750X. Generally, however, lower powers of perhaps 250X to 350X will be the maximum permissible, consistent with high image resolution. When unsteady air conditions prevail (as witnessed by rapid "twinkling" of the stars), extremely high-power eyepieces result in "empty magnification," where the object detail observed is actually diminished by the excessive power.

When beginning observations on a particular object, start with a low power eyepiece; get the object well-centered in the field of view and sharply focused; then try the next step up in magnification. If the image starts to become fuzzy as you work into higher magnifications, then back down to a lower power — the atmospheric steadiness is not sufficient to support high powers at the time you are observing. Keep in mind that a

Because of certain characteristics of the human eye (in particular, eye pupil diameter) and because of optical considerations inherent in the design of a telescope, there exists minimum practical powers. Generally speaking, the lowest usable power is approximately 4X per inch of telescope aperture, or about 28X in the case of the 7" telescope. During the daytime, when human eye pupil 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, and the 12" LX200 from 120X to 240X. It should be noted, however, that the higher magnifications may not be used due to atmospheric distortion caused by heat, moisture, and paniculate matter suspended in the air. Accessories are available both to increase and decrease the operating eyepiece power of the telescope. See your Meade dealer and the latest Meade Catalog for information on accessories.

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 table below lists the most common eyepieces available and the "Apparent Field" for each. 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/10

10" f/10

12" f/10

Eyepiece/Apparent Field

Power/Actual Field

Power/Actual Field Power/Actual Field

Power/Actual Field

Power/Actual Field

Power/Actual Field

 

 

 

 

Super Plossl Eyepieces (5-elements

; 1.25" O.D., except as noted)

 

 

6.4mm/52°

417/0.12°

200/0.26°

250/0.21°

313/0.17°

391/0.13°

476/0.11°

9.7mm/52°

275/0.19°

132/0.39°

165/0.32°

206/0.25°

258/0.20°

314/0.17°

12.4mm/52°

215/0.24°

103/0.50°

129/0.40°

161/0.32°

202/0.26°

246/0.21°

15mm/52°

178/0.29°

85/0.61°

107/0.49°

133/0.39°

167/0.31°

203/0.26°

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°

32mm/52°

83/0.63°

40/1 .30°

50/1 .04°

63/0.83°

78/0.67°

95/0.55°

40mm/44°

67/0.66°

32/1 .69°

40/1 .35°

50/0.88°

63/0.70°

76/0.53°

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 (6-elements; 1.25" O.D

., except as noted)

 

 

13.8mm/67°

193/0.35°

93/0.72°

116/0.58°

145/0.46°

181/0.37°

221/0.30°

1 8mm/67°

148/0.45°

71/0.94°

89/0.75°

111/0.60°

139/0.48°

169/0.40°

24.5mm/67°

109/0.61°

52/1 .28°

65/103°

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°

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 Eyepieces (8-elements; 1.25" O.D.,

except as

noted)

 

 

4.7mm/84°

568/0.15°

272/0.31°

340/0.25°

426/0.20°

532/0.16°

649/0.13°

6.7mm/84°

399/0.21°

191/0.44°

239/0.35°

299/0.28°

373/0.23°

455/0.18°

8.8mm/84° (1.25" - 2 '

O.D.)

303/0.28°

145/0.58°

182/0.46°

227/0.37°

284/0.30°

346/0.24°

14mm/84° (1.25" - 2 "

O.D.)

199/0.44°

91/0.92°

114/0.73°

143/0.59°

1 79/0.47°

218/0.39°

 

 

 

 

 

 

 

 

Page 23 Page 25
Image 24
Page 23 Page 25
Contents Meade Instruments Corporation Page ¬ WARNING! ¬ Contents What Is the LX200? An Overview Standard EquipmentIntroduction What You Should Have Please Look Everything OverInspecting the Optics Keypad Version NumberTelescope Assembly Field TripodUse the following steps to assemble your telescope Focusing the Viewfinder Mounting the ViewfinderAttaching the Viewfinder Collimating the ViewfinderUsing the LX200 Manually Using the LX200 In LandQuick Start Using the LX200 In Altaz Altazimuth Entering Basic InformationLocation of the Observing Site Setting Up the Telescope Local Time and DateUsing the Mode Key Library Object Keys Unknown SiteWhich Alignment Method to Use? Star AlignmentDirection Keys LX200 Keypad Hand ControllerLX200 Power Panel Mode Functions Page Page Backlash Object Library Menu File Enter Mode Two COORDINATES/GO to Mode Three CLOCK/CALENDARMode Four TIMER/FREQ a. Timer = Menu Option Coordinates Menu FileMode Five Keypad OFF/BRIGHTNESS Adjust For astrophotos60.0 Hz Solar Average rate for tracking Planetary rate Due to retrogradesApparent Field and Actual Field Magnification and Field of ViewMagnification Deluxe Latitude Adjuster Equatorial Wedge For 7 and 8 LX200Appendix a Equatorial Wedge Azimuth ControlSuperwedge For 10 and 12LX200 Mounting the Telescope On the WedgeSetting Magnetic Declination Compass InstallationMagnetic Compass Finding True North Appendix B Equatorial USE Celestial CoordinatesLining Up with the Celestial Pole Precise Polar Alignment Appendix C LX200 Alignmentstar Library Star Charts Alignment StarsStar Charts For Northern Hemisphere Observers Page SAO Catalog UGC CatalogCngc Catalog Object Library1C Catalog Gcvs CatalogStar Catalog Messier CatalogLittle Dumbbell Nebula 1x4.11200ly Double Cluster h Per 7klyTarantula Nebula Very Red Open Clus + Dneb Glob Clus D2 ST C1 S Bubble Nebula Red10.7x2.5 Capella BellatrixBeta Tau Alnath Beta Lep aStar Catalog Zuben Elschemali SeginusRigel Kentaurus B=1.3 BrachiumAldhibah Sabik A=3.0 B=3.5Ras Algethi Sarin B=8.8Sadalmelik Al Nair 302 Open Clus Sparse M93 Includes dark nebula Keeping Your Telescope Clean Appendix E Maintaining Your LX200Collimation of the Optical System Behind the Power Panel Right Ascension LockFactory Servicing and Repairs RS-232 Cable LX200 Test ProgramAppendix F LX200 Personal Computer Control LX200 Command Set Command Set FormatsGeneral Telescope Information Telescope Motion Home PositionLibrary/Objects Miscellaneous Finds the next object in a Find sequenceLX200 Demo Program Counter =REM Keys TelposKeyi Keys Appendix G LX200 Specifications TelescopeLX200I/10 10 LX200f/10 200 f/10 Page Field TripodFig Field Tripod collapsed Oak Canyon, Irvine, California 92618 2000Customer Service Introduction DC OperationAC Operation

LX20 specifications

The Leisure Time LX20 is an outstanding aquatic vehicle designed for leisure and recreational cruising. With its innovative design and advanced technology, it truly stands out in the world of personal watercraft. Built for performance and comfort, the LX20 is perfect for families, friends, or anyone looking to enjoy a day out on the water.

One of the main features of the LX20 is its spacious deck layout. The boat boasts ample lounge seating, providing enough room for passengers to relax and socialize while enjoying the beauty of nature. The ergonomic design of the seating ensures comfort during long excursions, whether you're fishing, sunbathing, or simply cruising along the coastline.

Powering the LX20 is a state-of-the-art engine, which offers impressive fuel efficiency without compromising on performance. The boat accelerates smoothly and reaches top speeds with minimal effort, making it suitable for water sports such as wakeboarding and tubing. The advanced hull design not only enhances stability and maneuverability but also ensures a smooth ride across choppy waters.

Technology plays a significant role in the LX20's appeal. Equipped with a user-friendly helm, the boat features an advanced navigation system, providing real-time GPS tracking, sonar capabilities, and weather alerts. This ensures that the captain can navigate with confidence, no matter where the adventure leads. The LX20 also includes Bluetooth speakers, allowing passengers to enjoy their favorite music while soaking up the sun.

Safety is a top priority in the design of the LX20. The boat is outfitted with essential safety features such as life jackets, fire extinguishers, and emergency flotation devices. The non-slip surfaces throughout the vessel minimize the risk of accidents, particularly when the boat is moving at high speeds or navigating rough waters.

In summary, the Leisure Time LX20 is a remarkable boat that caters to both adventure-seekers and those looking for relaxation. Its blend of spacious design, powerful engine, innovative technology, and strong safety features makes it an ideal choice for anyone who loves spending time on the water. Whether you’re planning a fishing trip, a family outing, or a leisurely cruise, the LX20 promises to deliver an unforgettable experience.
Top Page Image Contents