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This Telescope’s Optical System . . .

• Achromatic refractor optical tube: 6” aperture (1219mm focal length f/8) doublet, guaranteed to be diffraction-limited. The optical tube is 8” in diameter by 42” long. While chromatic aberration is visible on brighter objects, it is surprisingly well corrected for a 6” aperture scope. Collimation screws in the main objective cell allow fine-tuning of the objective lens alignment for peak image quality.

• Multicoated optics: Full multicoatings are standard equipment on all air to glass surfaces.

• Finderscope: 8 x 50mm straight-through achromatic design in a quick-release dual ring bracket. The finder has a wide 5.8° field of view that makes it easy to locate objects. Focuses by loosening the trim ring behind the objective lens cell, screwing the lens cell in or out to focus, and tightening the trim ring to lock in the correct focus.

• Focuser: 2” rack and pinion type, with removable 1.25” accessory adapter.

• Star diagonal: 1.25” prism type. For peak performance, some observers have found that upgrading the supplied star diagonal to a premium version, such as the TeleVue #7781C or #7781PC, pays visible dividends in sharpness and contrast during high magnification observing. A set of optional #895 vibration suppression pads under the tripod feet will likewise improve the telescope damping time for steadier high power observing.

• Eyepiece: 1.25” 26mm Super Plössl eyepiece (46x) with a 1.08° field of view (over two lunar diameters) for good wide-field images.

This Telescope’s Mount . . .

• Heavy duty LXD75 computerized German equatorial mount: The white-painted mount is machined of aluminum for durability and high-performance photo/visual observing. Four high-precision stainless steel ball bearings support the right ascension and declination axes for smooth motion in all directions. The mount has high-precision worm gear drives and electric slow motion controls in both right ascension and declination. Enhanced precision alignment of the motor gear assembly assures greatly reduced backlash and tracking smoothness. The dual-axis slewing/tracking motors have nine user-selectable slew and slow-motion speeds: 4.5°, 3°, and 1.5° per second; and 128x, 64x, 16x, 8x, 2x, and 1x the sidereal rate. Automatic sidereal-rate tracking in right ascension keeps objects precisely centered in the field for leisurely observing. Power for the dual-axis drives is supplied by a battery pack that rests on the telescope’s accessory shelf and plugs into the control panel. The pack uses eight (user-supplied) D-cell batteries that will power the scope for as long as 40 hours, depending on the temperature (low temperatures will reduce the usable battery life). Optional adapters with 25’ cords are available for uninterrupted AC and 12 volt DC car battery operation, as well.
      If serious long exposure astrophotography is in your plans, a supplied illuminated polar viewfinder and micrometric altitude and azimuth controls allow quick, precise polar alignment. A periodic error correction circuit in the computer control lets you train the mount to correct the small right ascension drive errors inherent in all telescope drive systems. This minimizes the number of guiding corrections needed during long exposure astrophotography. A high precision pointing subroutine in the computer lets you point accurately at objects that you want to photograph that are too dim to be seen though the scope.
      The mount’s sliding counterweights are locked in place with single hand-tighten levers, making it easy to rebalance the scope if you add heavy photographic accessories. The mount is easily capable of handling the scope and any reasonable combination of photographic accessories you might want to use. Snap-on covers keep the motor drives and polar alignment scope free from dust and debris.

• AutoStar computer hand control: The built-in Autostar dual-axis electronic control system has a database of 30,223 objects it can find and track for you. They are accessed using a 20-key alphanumeric keypad hand control on a 24” coiled cord. There are 13,235 non-stellar deep sky objects, including the complete Messier, Caldwell, IC, and NGC catalogs, although not all objects are visible in this size scope. There are also 16,888 stars sorted by name, SAO catalog number, and whether they are double or variable stars. You also get the 8 major planets; the Moon; 26 asteroids; 15 comets, and 50 Earth satellites. In addition, there are 200 memory locations available for storing your own user-defined objects, such as the coordinates of asteroids and new comets that are printed regularly in Astronomy and Sky & Telescope magazines. In addition to the 30,223 objects in its database, the Autostar can automatically move the scope to any object with known right ascension and declination coordinates.
      The Autostar hand control gives you a digital readout of r. a. and dec coordinates; scrolling information about the object being viewed; plus the results of calculations about sunrise, sunset, moonrise, moonset, moon phases, solar eclipses, lunar eclipses, the minimum of Algol, and more. Hypertext links on the Autostar screen display define many of the terms used in the computer (there's more than one megabyte of compressed text stored in the Autostar.) Built-in guided tours of the sky are tailored to the day of the year you are observing. They direct you to showpiece objects, including the Moon and any planets then visible. Most of the tour objects are accompanied by descriptions scrolling across the Autostar display (the description of Algol, for example, is over 300 words long). The Moon has different descriptions based on its phase, and prominent features near the terminator are highlighted.
      All of the database and scope operation information is displayed on a two line, 16-character, LED display on the hand control. A numeric keypad on the hand control gives complete control over the many, many Autostar functions and convenience features. On-screen operation instructions guide you through setup and use of the Autostar and a help function is only a keystroke away.
      The computer uses a three-star alignment method to precisely align the scope’s optical and mechanical systems on the heavens. Alignment is easily accomplished in only a few short minutes. You can be observing in less than 15 minutes after you first take the scope outdoors.

• Adjustable height tripod: The tripod has tubular chromed steel legs. Each leg has two anodized aluminum leg extension locks with an internal brake to eliminate accidental slippage of the internal extending leg section. These locks face inwards to prevent snagging your clothing or gouging your shin as often happens when running into outward-facing leg locks in the dark. A center leg brace adds rigidity and excellent damping characteristics. The center leg brace is drilled to form a convenient accessory tray that holds three 1.25” eyepieces to keep them up out of the dew-soaked grass.

• Dovetail slide bar: An adjustable dovetail slide bar allows the optical tube to be quickly and precisely balanced fore and aft on the mount, eliminating the need for an extra counterweight to balance a camera or other accessories. Setup and takedown times are exceptionally fast, as a single large hand-tighten knob holds the optical tube in place. A second lock knob prevents the tube from sliding off the mount should the hand-tighten knob loosen.

What can you see through this scope:

    At your command, the supplied Autostar computer moves the 5” LXD75 effortlessly and automatically from major planet to asteroid to galaxy to nebula at a rapid 4.5° per second, placing each object in the center of the eyepiece field for your leisurely inspection with about 15 arc minute accuracy. Deep-space objects, from the core of bright galaxies like Andromeda (M31) to faint nebulas like NGC 6559 in Sagittarius – and thousands of other galaxies, nebulas, and star clusters – take on added brightness and detail of form and structure when compared with the view through a similarly-priced 5” scope. Significantly increased detail is visible on the Moon and planets using optional eyepieces and/or Barlows. You can resolve craterlets in the floor of Plato, observe discontinuities in the ice cap on Mars, and study the transits of Jupiter’s moons and the changing patterns in Jupiter’s cloud belts. You can study craters, hairline rilles, mountain ranges, and low contrast lunar ray detail at high magnification as you range over the surface of the Moon using the Autostar’s pushbutton slow-motion controls.
    Very full featured and surprisingly reasonable in cost for a refractor of this large an aperture, the go-to computerized 6” LXD75 can take you on a journey through the skies that you will treasure for years to come.