Features of this Telescope's Optical System . . .

• Oversized primary mirror: The diameter of the primary mirror of each LX200GPS is larger than the diameter of the Schmidt 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 SCT 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 float glass Schmidt 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 scope's 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 or very high magnification visual observing. 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.