Knowledge Base

Features of this Optical Tube's Optical System . . .

• Advanced Coma-Free catadioptric designed to emulate the optical performance of a Ritchey-Chrétien telescope: The traditional two-mirror Ritchey-Chrétien (RC) design uses hyperbolic primary and secondary mirrors to produce images that are free from coma over a wide field. Because of this wide coma-free field and a relatively fast focal ratio, the Ritchey-Chrétien design is particularly well suited to astrophotography. The RC is the design of choice for most of the major professional observatory telescopes built in the last half-century. For example, the Hubble Space Telescope and the twin 10-meter Keck telescopes in Hawaii are Ritchey-Chrétiens.
  

      However, fabricating and testing a large aperture hyperbolic mirror is a very complex task (just ask the people who built the initially-flawed, with the flaw not discovered until it was in space, Hubble Space Telescope). That is why traditional two-mirror Ritchey-Chrétiens are expensive to manufacture and purchase, often too expensive for many amateur astronomers.
  

      To emulate the coma-free performance of a true RC telescope, while keeping the cost within reason, the Meade Advanced Coma-Free (ACF) catadioptric optical system uses a full aperture aspheric corrector lens in conjunction with a simple spherical primary mirror. This creates a two-element primary mirror system that performs like an RC's single hyperbolic primary mirror from the optical point of view of the secondary mirror.
  

      The hyperbolic secondary mirror itself is mounted directly on the rear of the corrector lens, rather than in the traditional RC's conventional spider vane assembly. This eliminates the image-degrading diffraction spikes of the secondary mirror support structure visible in commercial RC scope images. The result is RC-class coma-free wide-field performance, at about a fourth the cost of most true RC systems.
  

      The corrector-modified design would itself be expensive to fabricate were it not for Meade's more than a quarter-century of experience making Schmidt-Cassegrain correctors, which are in the same optical family as the corrector needed for the coma-free design of this optical tube. An additional benefit of the full aperture corrector in the ACF design is slightly better correction for astigmatism than the traditional RC design.
  

      In addition, an ACF optical system, due to its front corrector plate, is a closed tube design. This keeps the primary optical components protected from dust, moisture and other contaminants that might fall on the optical surfaces of the primary and secondary mirrors as can happen with the traditional open-tube RC design.
  

      While an ACF optical system may not be a traditional RC design, its performance is RC-like in all important characteristics. A review in Sky & Telescope magazine of the predecessor of the Meade ACF optics said the bottom line is that the optics do "indeed perform like a Ritchey-Chrétien." Another such review, in Astronomy magazine said, "This scope delivers Ritchey-Chrétien-like performance at a fraction of the cost."
  

• Oversized primary mirror: The diameter of the primary mirror of each ACF optical tube is larger than the diameter of the corrector lens at the front of its optical tube that admits the light. The primary mirror of the 8" scope is actually 8.25" in diameter, compared to the 8" diameter of the corrector lens. The 10" primary is 10.375" in diameter; the 12" is 12.375"; the 14" is 14.57"; and the 16" primary is 16.375" in diameter. Oversizing the primary mirror in this way gives you a wider fully-illuminated field than a conventional catadioptric scope whose corrector and primary mirror are the same size. The result is a gain of 5% to 8% more off-axis light available to your eye or camera, depending on the telescope model.
  

• Fully multicoated UHTC (Ultra High Transmission Coatings) optics: The primary and secondary mirrors are vacuum-coated with aluminum, enhanced with multiple layers of titanium dioxide and silicon dioxide for increased reflectivity. A overcoating layer of durable silicon monoxide (quartz) assures long life.
  

      A series of anti-reflective coatings of aluminum oxide, titanium dioxide, and magnesium fluoride are vacuum-deposited on both sides of the full aperture corrector plate. These antireflection multicoatings provide a high 99.8% light transmission per surface, versus a per-surface transmission of 98.7% for standard single-layer coatings.
  

      UHTC multicoatings provide a 15% increase in light throughput compared with standard single-layer coatings. They effectively add the equivalent of 15% extra light-gathering area to the performance of a scope with standard coatings. It's the equivalent of three-quarters of an inch of extra aperture in the case of a 10" scope, for example, but with no increase in actual size or weight. UHTC coatings also improve contrast, for lunar and planetary images that appear sharper and more crisply defined.
  

• Fully baffled optics: A cylindrical baffle around the secondary mirror, in combination with the cylindrical baffle tube projecting from the center of the primary mirror, prevents stray off-axis light from reaching the image plane. In addition, a series of field stops machined into the inner surface of the central baffle tube effectively eliminates undesirable light which might reflect from the inside surface of the tube. The result of these baffle systems is improved contrast in lunar, planetary, and deep space observing alike.
  

• Mirror lock: A progressive tension lock knob on the rear cell locks the telescope's primary mirror rigidly in place once a photographic manual focus has been achieved. Locking the mirror eliminates the possibility of mirror shift (the image moving from side to side as the optical tube passes from one side of the zenith to the other). Mirror shift, once the bane of CCD astrophotographers because it could blur the image without the astrophotographer being aware of it until the image was examined later during the processing stage, is non-existent with the Meade system.

   Celestron EdgeHD high definition optics are aplanatic, or corrected for spherical aberration. They are essentially conventional Schmidt-Cassegrain optics (spherical primary mirror, spherical secondary mirror, and full-aperture Schmidt aspheric corrector lens), but with the addition of a dual-element multicoated field flattener lens installed in their central baffle tube. The field flattener is designed to reduce off-axis coma and produce aberration-free images across a wide visual and photographic field of view.

   In addition to reduced off-axis coma, the EdgeHD optical system delivers an astrograph-quality flat focal plane across the entire field. Many optical designs that advertise themselves as "astrograph" quality actually produce their pinpoint stars across a curved focal plane. While this may be acceptable for visual observing, stars appear out of focus at the edge of the field when used with the flat rectangular imaging sensor of a DSLR digital camera or a large format CCD. The built-in field flattener of the EdgeHD optical system produces a focal plane more than three times flatter than a standard Schmidt-Cassegrain telescope and dramatically flatter than other competing coma-free designs. This guarantees visibly sharp stars across some of the largest CCD and DSLR chips available today.

   The superior edge performance of the EdgeHD optic system not only creates rounder, more point-like, and more pleasing stars at the edge of the field but actually improves the resolution and limiting magnitude when compared to telescopes of equal aperture. Poor edge quality or field curvature in conventional optics can spread out a star's image at the edge of the field so much so that the brightness of a star appears the same as the sky background, making it undetectable to your eye (or camera). EdgeHD optics give you smaller (more concentrated) stars that create brighter images that pop out of the sky background, allowing you to see down to a fainter magnitude. This lets you capture fainter stars and galaxies out to the corners of your full frame camera chip than is possible with conventional telescope designs of equal aperture.

The LCM mount's single fork arm is made of die cast aluminum. It is rigid and damps vibrations quickly. The optical tube mounts onto the fork arm using a no-tool quick-release dovetail bracket for fast set-up, take-down, and balancing. This allows you to use the mount with other lightweight optical tubes that have the appropriate dovetail.

    The mount includes pre-installed enclosed dual DC servo motor drives - one for moving the scope in altitude (up/down) and one for azimuth (right/left). The combined motion of the two motors allows the scope to move smoothly in an arc across the sky, following the seemingly curved path taken by the stars and planets. Built-in electronics let you select the appropriate lunar, solar, or sidereal (star) tracking rate to keep each specific kind of object centered in the field of view so that several people can observe at their leisure without having constantly to adjust the position of the scope. The electronics also give you a choice of nine different slewing and centering speeds for locating objects (3°/sec, 2°/sec, 1°/sec, 0.5°/sec, and 32x/16x/8x/4x/2x the sidereal rates).

    A compartment in the drive base holds eight user-supplied AA batteries for powering the telescope. All power connections to the motors are internal. This eliminates the cord wrap problems you often find with competitive telescopes powered by an external battery pack that connects to the scope through a dangling power cord.

    To conserve battery life when the telescope is being used in the backyard, an optional AC adapter (#2338N) is available to operate the scope from an extension cord connected to a normal household 110 VAC electric outlet. The Celestron Power Tank (#4512V) is also a highly recommended optional accessory if you observe away from home a lot. This is a 7 amp-hour capacity multi-purpose rechargeable 12V DC battery that can provide several nights worth of observing from a single charge when you're in the field away from backyard AC.

    The underside of the mount's drive base has three round feet that rest on three flat pads inside the tripod head. The drive base is held in place on the tripod by one large hand-tighten knob in the underside of the tripod. Assembly is fast and foolproof. There is no need to fumble with multiple mounting bolts, or try to align mounting bolts in a tripod with holes you can't see in the base of the mount, as is the case with competitive scopes. The LCM mount's no-tool assembly is foolproof and takes only a few seconds.

    The preassembled adjustable-height tripod has aluminum legs that damp vibrations quickly. The center leg brace holds a convenient no-tool quick-release accessory tray to keep your eyepieces and accessories up and out of the dew-soaked grass. The locking levers for the tripod leg height adjustment face are on the sides of the legs, so they won't snag your clothing as you move around the tripod in the dark. A bubble level in the center of the drive base lets you level the tripod for more accurate tracking of celestial objects.

LCM Computer Hand Control: The supplied NexStar-based LCM computer hand control has an illuminated numeric keypad and a two-line 16-character LCD display. It stores in a holder that clips to one of the tripod legs. The telescope can be operated with the ergonomically-designed hand control conveniently docked in its holder. You can also remove the control and its coiled connecting cord from the holder for hand-held use. There is no need to worry about wrapping the cord around the mount as you walk around the scope to observe different parts of the sky. The hand control plugs into the fork arm rather than the drive base, so it always moves with the scope.

    The LCM computer has a database of 4,033 stars and objects that it can locate and track for you. The database includes the complete Messier and Caldwell catalogs of famous deep space objects; a selection of the brightest and best deep space objects from the Revised New General Catalog (NGC); selected SAO stars, including the best variable stars and multiple star systems; the planets; the Moon; the Sun; and more.

    With the LCM computer's hand control, you can select an object catalog at the touch of a button; automatically slew to any of the 4,033 objects in its memory, including over 600 galaxies, 300 star clusters, and dozens of beautiful binary stars; move to objects not in it's data base under your command; change the slew speed; view fascinating information about an object, including enhanced information on many of the particularly fascinating objects; or simply determine if a desired object is visible in the sky. It can automatically take you on guided tours of the best objects visible in your sky the night you are observing, any night of the year. The computer's hand control/database software and motor drive software can be flash upgraded via the internet so you will always have the most up-to-date software version available.

SkyAlign Technology: With Celestron's SkyAlign technology, you don't have to know Altair from Zubenelgenubi or know how to read a star chart to line up your LCM telescope on the sky. There is also no need to point the telescope north and level the optical tube or to pay extra for a competitive scope that levels the scope and points it north for you. With SkyAlign, the initial position of the telescope is irrelevant. Trees and buildings can block your view of the north celestial pole and you'll still be able to properly align the scope on the sky. This makes for fast and very easy alignment of the telescope every time you take it out to observe.

    Simply input the date, time, and your location into the computer hand control. The LCM computer has a U.S. and international city database that lets you easily set your observing location. It will normally default to your last observing site automatically, but you can change to a new observing site anytime you want.

    Once you've entered the date, time, and location, use the StarPointer red dot LED finder to align the telescope on any three bright stars, or to two stars and a bright planet or even the Moon. You don't need to know the names of the stars or the planet. The LCM computer system will automatically determine which objects were chosen and then generate an internal map of the sky that will let it move automatically to any star or object you select for the rest of the night. It does it by calculating the angles and distances measured between the objects you've chosen and then compares them to the known separations between objects. Using this method, the telescope determines what objects were chosen. The display will tell you which three objects you aligned to for confirmation.

    Only two of the alignment objects will actually be used for calculating the model of the sky that the computer uses for locating objects. The third object simply provides a positive identification of the other two. Therefore, at least two of the three alignment objects should be spaced at least 60 degrees apart in the sky if possible, and the third object should not fall in a straight line between the first two alignment stars.

    Since the brightest stars appear first as the sky darkens at dusk, the SkyAlign system is exceptionally easy to set up and use as night comes on. You don't have to guess which stars are brightest, as only the brightest will be visible in the early evening. The same holds true for observers from a light-polluted suburban site, where only the brightest stars are visible to the unaided eye.

    Other alignment methods are also built into the LCM computer. Auto Two-Star Align asks you to choose and center the first alignment star, then the LCM computer automatically selects and slews to a second star for alignment. Two-Star Align lets you identify and manually slew your telescope to the two alignment stars. One-Star Align is the same as Two-Star Align, but only requires you to align to one known star. Although not as accurate as the other alignment methods, One-Star Align is the quickest way to find and track bright planets and objects in Altazimuth mode. Finally, Solar System Align displays a list of visible daytime objects (planets, the Moon, and the Sun) available to align the telescope for observing during the day.

    Once the scope has aligned itself with the sky, it takes only a few keystrokes on the computer hand control to have the scope move automatically to your first observing target and start tracking it so you can observe at your leisure. You can find hundreds of fascinating deep space objects your first night out, even if you have never used a telescope before. No matter what level of experience you start from, your Celestron LCM scope will unfold all the wonders of the Universe for you, your family, and your friends.

Features of this Telescope's Optical System . . .

• Modified Ritchey-Chrétien optical design: The traditional two-mirror Ritchey-Chrétien (RC) design uses approximately hyperbolic primary and secondary mirrors to produce images that are free from coma over a wide field. Because of this wide field and a relatively fast focal ratio, the Ritchey-Chrétien design is particularly well suited to astrophotography. The RC is the design of choice for most of the major professional observatory telescopes built in the last half-century. For example, the Hubble Space Telescope and the twin 10-meter Keck telescopes in Hawaii are Ritchey-Chrétiens. However, because of the complexity of fabricating and testing a large aperture hyperbolic mirror (just ask the people who built the Hubble Space Telescope), traditional two-mirror Ritchey-Chrétiens are very expensive to manufacture and purchase.
      To keep the cost of the LX200R Ritchey-Chrétien optical system more reasonable, its modified Ritchey-Chrétien design uses a full aperture aspheric corrector lens in conjunction with a simple spherical primary mirror. This creates a two-element primary mirror system that performs like a single hyperbolic mirror from the optical point of view of the secondary mirror. The secondary mirror itself is mounted directly on the rear of the corrector lens, rather than in the traditional RC's conventional spider vane assembly. This eliminates the image-degrading diffraction spikes of the secondary mirror support structure visible in other commercial RC scopes. The result is RC-class wide-field performance at about a fourth the cost of a pure RC system.
      The corrector-modified design would itself be expensive to fabricate were it not for Meade's quarter-century of experience making Schmidt-Cassegrain correctors, which are in the same optical family as the corrector needed for the modified RC design. An additional benefit of the full aperture corrector in the modified RC design is slightly better correction for astigmatism than a traditional RC scope. In addition, the LX200R, due to the front corrector plate, is a closed tube design. This keeps the primary optical components protected from dust, moisture and other contaminates that might fall on the optical surfaces of the primary and secondary mirrors as with traditional open-tube RC designs. While the LX200R may not be a traditional RC design, its performance is RC-like in all important characteristics.
      A review in Sky & Telescope magazine of the Meade RCX400 Ritchey-Chrétien optics (which are identical to those used in the LX200R) said, "the bottom line is that the RCX400 does indeed perform like a Ritchey-Chrétien." Another RCX400 optics review, in Astronomy magazine said, "This scope delivers Ritchey-Chrétien-like performance at a fraction of the cost."

• Oversized primary mirror: The diameter of the primary mirror of each LX200R is larger than the diameter of the corrector lens at the front of its optical tube that admits the light. The primary mirror of the 8" scope is actually 8.25" in diameter, compared to the 8" diameter of the corrector lens. The 10" primary is 10.375" in diameter; the 12" is 12.375"; the 14" is 14.57"; and the 16" primary is 16.375" in diameter. Oversizing the primary mirror in this way gives you a wider fully-illuminated field than a conventional catadioptric scope whose corrector and primary mirror are the same size. The result is a gain of 5% to 8% more off-axis light available to your eye or camera, depending on the telescope.

• Fully coated optics: The Pyrex primary and secondary mirrors are vacuum-coated with a thin layer of aluminum that provides approximately 89% reflectivity per surface. Once aluminized, the mirrors are overcoated with a protective layer of silicon monoxide (quartz) for long life.
      A thin layer of anti-reflection magnesium fluoride is vacuum deposited on both sides of the clear water white glass corrector plate (BK7 optical glass in the case of the 16" scopes for increased IR and UV transmission for scientific measurements) to provide a high 98.7% light transmission per surface, compared to the 96% transmission of uncoated glass. Overall light throughput (the amount of light collected by the objective lens that actually reaches your eye or camera) is approximately 77% at the Cassegrain focus.
      For those interested in even more brightness for photography and observing faint deep space objects, Meade also offers this scope with optional UHTC (Ultra High Transmission Coatings) for a 15% increase in light throughput. Optional UHTC multicoatings effectively add the equivalent of extra light-gathering aperture to the performance of a scope with standard coatings (the equivalent of three-quarters of an inch of extra aperture in the case of a 10" scope, for example), but with no increase in actual size or weight.

• Fully baffled optics: A cylindrical baffle around the secondary mirror, in combination with the cylindrical baffle tube projecting from the primary mirror, prevents stray off-axis light from reaching the image plane. In addition, a series of field stops machined into the inner surface of the central baffle tube effectively eliminates undesirable light which might reflect from the inside surface of the baffle tube. The result of these baffle systems is improved contrast in lunar, planetary, and deep space observing alike.

• Mirror lock: A progressive tension lock knob on the rear cell locks the telescope's primary mirror rigidly in place once an approximate manual focus has been achieved. The standard equipment electric focuser, described below, is then used for fine focusing. Locking the mirror eliminates the possibility of mirror shift (the image moving from side to side while focusing, caused by the primary mirror tilting on the central baffle tube as the mirror moves fore and aft along the tube). Mirror shift, once the bane of CCD astrophotographers because it could easily move the image off a small CCD chip, is non-existent with the Meade system.

• Electric focuser: The supplied zero image-shift electric microfocuser is controlled by the Autostar II computer hand control. It moves an externally-mounted eyepiece or camera to focus, rather than moving the primary mirror. This eliminates mirror shift during precise image centering and focusing for CCD applications. The microfocuser has four different operating speeds, from very fast down to an extremely slow creep, giving you focusing accuracy to a truly microscopic level during critical visual and astrophotographic applications.
      The focuser is designed to hold 2" star diagonals and eyepieces. A supplied 1.25" adapter allows the use of 1.25" diagonals and eyepieces in the 2" focuser. Another supplied adapter duplicates the 2" rear cell thread used on Schmidt-Cassegrain telescopes to allow the use of off-axis guiders, T-adapters, etc. A 1.25" visual back is not supplied with the scope. If you want to do high magnification eyepiece projection photography of the Moon and planets, you will have to add an optional 1.25" visual back #9135 and a tele-extender to the focuser's supplied 2" rear cell thread adapter.

Features of this Telescope's Optical System . . .

• Modified Ritchey-Chrétien optical design: The traditional two-mirror Ritchey-Chrétien (RC) design uses approximately hyperbolic primary and secondary mirrors to produce images that are free from coma over a wide field. Because of this wide field and a relatively fast focal ratio, the Ritchey-Chrétien design is particularly well suited to astrophotography. The RC is the design of choice for most of the major professional observatory telescopes built in the last half-century. For example, the Hubble Space Telescope and the twin 10-meter Keck telescopes in Hawaii are Ritchey-Chrétiens. However, because of the complexity of fabricating and testing a large aperture hyperbolic mirror (just ask the people who built the Hubble Space Telescope), traditional two-mirror Ritchey-Chrétiens are very expensive to manufacture and purchase.
      To keep the cost of the LX200R Ritchey-Chrétien optical system more reasonable, its modified Ritchey-Chrétien design uses a full aperture aspheric corrector lens in conjunction with a simple spherical primary mirror. This creates a two-element primary mirror system that performs like a single hyperbolic mirror from the optical point of view of the secondary mirror. The secondary mirror itself is mounted directly on the rear of the corrector lens, rather than in the traditional RC's conventional spider vane assembly. This eliminates the image-degrading diffraction spikes of the secondary mirror support structure visible in other commercial RC scopes. The result is RC-class wide-field performance at about a fourth the cost of a pure RC system.
      The corrector-modified design would itself be expensive to fabricate were it not for Meade's quarter-century of experience making Schmidt-Cassegrain correctors, which are in the same optical family as the corrector needed for the modified RC design. An additional benefit of the full aperture corrector in the modified RC design is slightly better correction for astigmatism than a traditional RC scope. In addition, the LX200R, due to the front corrector plate, is a closed tube design. This keeps the primary optical components protected from dust, moisture and other contaminates that might fall on the optical surfaces of the primary and secondary mirrors as with traditional open-tube RC designs. While the LX200R may not be a traditional RC design, its performance is RC-like in all important characteristics.
      A review in Sky & Telescope magazine of the Meade RCX400 Ritchey-Chrétien optics (which are identical to those used in the LX200R) said, "the bottom line is that the RCX400 does indeed perform like a Ritchey-Chrétien." Another RCX400 optics review, in Astronomy magazine said, "This scope delivers Ritchey-Chrétien-like performance at a fraction of the cost."

• Oversized primary mirror: The diameter of the primary mirror of each LX200R is larger than the diameter of the corrector lens at the front of its optical tube that admits the light. The primary mirror of the 8" scope is actually 8.25" in diameter, compared to the 8" diameter of the corrector lens. The 10" primary is 10.375" in diameter; the 12" is 12.375"; the 14" is 14.57"; and the 16" primary is 16.375" in diameter. Oversizing the primary mirror in this way gives you a wider fully-illuminated field than a conventional catadioptric scope whose corrector and primary mirror are the same size. The result is a gain of 5% to 8% more off-axis light available to your eye or camera, depending on the telescope.

• Fully multicoated UHTC (Ultra High Transmission Coatings) optics: The primary and secondary mirrors are vacuum-coated with aluminum, enhanced with multiple layers of titanium dioxide and silicon dioxide for increased reflectivity. A overcoating layer of silicon monoxide (quartz) assures long life.
      A series of anti-reflective coatings of aluminum oxide, titanium dioxide, and magnesium fluoride are vacuum-deposited on both sides of the full aperture corrector plate. These antireflection multicoatings provide a high 99.8% light transmission per surface, versus a per-surface transmission of 98.7% for standard single-layer coatings. Overall light throughput (the amount of light collected by the objective lens that actually reaches your eye or camera) is approximately 89% at the Cassegrain focus.
      UHTC multicoatings provide a 15% increase in light throughput compared with standard coatings. They effectively add the equivalent of 15% extra light-gathering area to the performance of a scope with standard coatings. It's the equivalent of three-quarters of an inch of extra aperture in the case of a 10" scope, for example, but with no increase in actual size or weight. UHTC coatings also improve contrast, for lunar and planetary images that appear sharper and more crisply defined.

• Fully baffled optics: A cylindrical baffle around the secondary mirror, in combination with the cylindrical baffle tube projecting from the primary mirror, prevents stray off-axis light from reaching the image plane. In addition, a series of field stops machined into the inner surface of the central baffle tube effectively eliminates undesirable light which might reflect from the inside surface of the baffle tube. The result of these baffle systems is improved contrast in lunar, planetary, and deep space observing alike.

• Mirror lock: A progressive tension lock knob on the rear cell locks the telescope's primary mirror rigidly in place once an approximate manual focus has been achieved. The standard equipment electric focuser, described below, is then used for fine focusing. Locking the mirror eliminates the possibility of mirror shift (the image moving from side to side while focusing, caused by the primary mirror tilting on the central baffle tube as the mirror moves fore and aft along the tube). Mirror shift, once the bane of CCD astrophotographers because it could easily move the image off a small CCD chip, is non-existent with the Meade system.

• Electric focuser: The supplied zero image-shift electric microfocuser is controlled by the Autostar II computer hand control. It moves an externally-mounted eyepiece or camera to focus, rather than moving the primary mirror. This eliminates mirror shift during precise image centering and focusing for CCD applications. The microfocuser has four different operating speeds, from very fast down to an extremely slow creep, giving you focusing accuracy to a truly microscopic level during critical visual and astrophotographic applications.
      The focuser is designed to hold 2" star diagonals and eyepieces. A supplied 1.25" adapter allows the use of 1.25" diagonals and eyepieces in the 2" focuser. Another supplied adapter duplicates the 2" rear cell thread used on Schmidt-Cassegrain telescopes to allow the use of off-axis guiders, T-adapters, etc. A 1.25" visual back is not supplied with the scope. If you want to do high magnification eyepiece projection photography of the Moon and planets, you will have to add an optional 1.25" visual back #9135 and a tele-extender to the focuser's supplied 2" rear cell thread adapter.

The built-in Sony GPS (Global Positioning Satellite) receiver and the AutoAlign software in the built-in AutoStar computer make aligning on the sky almost as easy as simply turning on your telescope. Take your LX90 outside and set it up on its supplied tripod. Turn it on. The LX90's GPS receiver uses the radio signals from Earth-orbiting satellites to determine the telescope's location on Earth with an accuracy measured in meters. From this information about where and when on Earth the telescope is located, the AutoAlign software determines what the sky looks like overhead and moves the telescope automatically to its first alignment star.
    If the star is not precisely centered in the crosshairs of the supplied 8 x 50mm finderscope, you use the AutoStar hand control pushbuttons to center it to improve the pointing accuracy. Let the scope repeat the process for its second alignment star and you're ready to start observing. The GPS/AutoAlign system makes aligning your LX90 and finding your way around the night sky exceptionally easy, even for the first-time telescope owner.

The LX90's AutoStar computer hand control plugs into the telescope's fork arm to permit a wide array of telescope options. First and foremost is its automatic go-to capability. The AutoStar computer can show you the planets and thousands of deep space objects the very first night you use your scope - even if you've never used a telescope before! At the push of a button, the LX90 will move at a fast 6.5° per second to any of the 30,223 objects in its database. You can choose from 13,235 deep-sky objects from the complete Messier, Caldwell, IC, and NGC catalogs (sorted by name and type). Also included are 16,888 stars sorted by name, SAO catalog number, and by whether they are double or variable stars.
    The AutoStar will also locate the centroids of all 88 constellations and 50 objects in the solar system (8 major planets from Mercury to Pluto; the Moon; 26 asteroids; and 15 periodic comets). You can use it to track 50 Earth satellites, including the International Space Station, the Hubble space telescope, and Mir, plus any of 200 user-defined objects. You can also automatically move to any object that's not in the database simply by entering its right ascension and declination coordinates. The AutoStar moves the LX90 at any of nine user-selectable slewing and guiding speeds: 6.5°/sec, 3°/sec, and 1.5°/sec for slewing and centering; as well as 128x, 64x, 16x, 8x, and 2x the sidereal rate for centering and astrophotographic guiding. In addition, there are standard lunar and sidereal tracking rates, plus a user-defined drive rate for precision tracking of the Sun and planets. The AutoStar includes a Smart Drive dual-axis drive corrector for long-exposure guided astrophotography (when used with an equatorial wedge in the polar mode). The Smart Drive has permanent periodic error correction that can be trained for finer and finer drive accuracy. You can even connect an optional #909 accessory port module to the rear cell of the LX90 to allow completely automatic CCD autoguiding of long exposure photos. The #909 also allows the use of an optional electric focuser and illuminated reticle eyepiece.
    The AutoStar computer includes hundreds of special event menus, guided tours, a glossary, utility functions, and telescope status options. It also allows fast alignment of the telescope in either an equatorial or altazimuth mode using any of three alignment methods, including Meade's proprietary Easy Align method.
    The altazimuth drive of the LX90 is more than accurate enough for piggyback, lunar, and planetary 35mm photos and much CCD imaging. However, field rotation causes stars at the corners of an image to streak during exposures longer than five minutes if you don't use an equatorial wedge to align the scope on the celestial pole. So, if you plan on doing long exposure deep space photography, you'll need to add the optional #2590 LX90 equatorial wedge to your 8" scope, and the #2570 Ultrawedge to your 10" or 12" scope.