More Information  · Supplied Accessories  · Recommended Accessories  · Images of Some Features

This Telescope’s Optical System . . .

• Schmidt-Newtonian optical tube: 8” aperture (812mm focal length f/4), guaranteed to be diffraction-limited. The primary and diagonal mirrors are crafted of low thermal expansion Pyrex optical glass. The Schmidt corrector lens is made of water white glass, for up to 10% higher light transmission than conventional soda-lime (plate) glass. The Schmidt corrector has a subtle aspheric curve ground into it that reduces the primary mirror’s coma (an optical defect that turns pinpoint stars at the edge of the field into wedges or seagull shapes) to only one-half that of a conventional parabolic-mirror Newtonian reflector of the same focal ratio. The result is pinpoint star images over an extremely wide field and visibly sharper views edge to edge. The optics, made entirely at Meade’s Irvine, CA, optical shop, are mounted in machined aluminum cells that are fitted to a white-enameled steel tube.

• UHTC (Ultra High Transmission Coating) multicoated optics: The primary and diagonal mirrors are vacuum-coated with aluminum, enhanced with multiple layers of titanium dioxide and silicon dioxide for increased reflectivity. These multicoatings are then overcoated with a protective layer of silicon monoxide (quartz) for long life. A series of anti-reflective coatings of aluminum oxide, titanium dioxide, and magnesium fluoride are vacuum-deposited on both sides of the water-white float glass Schmidt corrector plate. UHTC multicoatings provide a 15% increase in light throughput (the amount of light collected by the objective lens that actually reaches your eye or camera), when compared with standard coatings. These coatings effectively add the equivalent of six-tenths of an inch of light-gathering aperture to the scope, with no increase in the size or weight of the scope. The UHTC multicoatings also improve contrast, for lunar and planetary images that appear sharper and more crisply defined.

• 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.

• Eyepiece: 1.25” 26mm Super Plössl eyepiece (32x) with a 1.6° field of view (over three lunar diameters) and a huge 6.5mm exit pupil for brilliant, low power rich-field images of nebulas, galaxies, and star clusters. High-power lunar and planetary images, using optional eyepieces and/or Barlows, reveal subtle details that are often lost in telescopes of lesser optical resolution.

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 two sliding counterweights are locked in place with a single hand-tighten lever each, 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. A set of optional #895 vibration suppression pads under the tripod feet will even further improve telescope damping time for steadier high power observing. 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 8” 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. While the fast focal ratio of the scope is designed for brilliant performance on the faint fuzzies outside the solar system, high-power lunar and planetary images are not slighted. Using optional eyepieces and/or a Barlow to boost the magnification, you can see subtle solar system details that are often lost in telescopes of lesser optical resolution. 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. With good seeing conditions, you can often see Jupiter’s cloud belts as a web of intricate discontinuities and festoons and observe transits and shadow transits of Jupiter’s main satellites. Six of Saturn’s satellites can be seen revolving about the planet and you can easily resolve Cassini’s division in Saturn’s rings (and it is possible to occasionally resolve the much more difficult Encke’s division, as well).
    The Meade SN-8 AT Schmidt-Newtonian reflector with UHTC multicoatings has enough aperture and resolution to keep you busy observing for the rest of your life. It has enough useful computerized features to handle almost any observing chore you set for it . . . at a price that won’t break the bank. Full featured and surprisingly reasonable in cost, the fully computerized 8” LXD75 can show you virtually the entire universe for years to come for little more than the cost of a cup of coffee a day.