Meade 14" LX200-ACF Advanced Coma-Free OTA
- Meade 14" f/10 LX200-ACF Optical Tube Assembly with UHTC
- Dust Caps
So, you're finally planning on buying your first telescope. Well, good for you! Once you've made up your mind however, you are likely to delve into a bottomless pit of information out there before you find what you are looking for. You'll come across words like "Catadioptric", "Refractor" and "Reflector". And you may even go all starry eyed when you hear words like "Coma free" and "Meade UHTC" or "Meade AutoStar" bantered around too. Don't be confused. We'll try to make sense of all of it all for you here.
The best telescope you could possibly hope to purchase would be a Meade LX-200 ACF 14 inch computerized telescope. And that's because it is based on Catadioptric technology. Traditional scopes are either Reflector-based, using combinations of concave and flat mirrors, or Refractor-based, using lenses to process their images. The Meade LX200 ACF series of telescopes represent the best of both these worlds, blending a combination of mirrors (catoptric) and lenses (dioptrics) to bring you Hubble Telescope-class celestial imagery that other scopes lack.
And you want your scope to look like an engineering marvel. Strong in built, sleek in looks, and heavy to the touch. And the Meade LX-200 ACF 14 inch computerized telescope fits the bill perfectly. With its heavy duty mount, which supports dual forks, you can easily manoeuvre the heavy Meade LX200 ACF scope with relative ease. The mount has been designed to deliver precision-perfect ability to swerve in increments of .1 degrees as quickly as 1 to 8 degrees per second. Alternately, if you prefer a fine swerve, the Meade LX200 ACF telescopes can do that to .01x to 1x sidereal in 1 1/100th increments. And using Meade's Smart Mount technology, the mount continually refines your pointing accuracy whenever you center an object in your scope. Once mounted, your first telescope will think on its own feet. How cool is that!
Through its continued innovation, Meade strives to bring the best possible professional astronomer-class technology to your backyard. All Meade LX200 ACF telescopes therefore feature Meade's patented breakthrough Advanced Coma Free (ACF) technology. Other Schmidt-Cassegrain scopes available in the market today will present you with hazy and blurry images of stars, planets and constellations. The cause of such problems is "coma" or a diffraction of light coming into the scope. The Meade LX200 ACF series of scopes use ACF technology to bring you clear, crisp images devoid of any distortions. By concentrating starlight even more precisely than any other device available today, the Meade LX-200 ACF 14 inch computerized telescope is even able to produce fuller, rounder and perfectly formed images of planetary objects that are far more distant and fainter. And that's the kind of feature you want in your very first scope!
And once you have located your target celestial object, you would like to view it for hours, taking in all of its heavenly beauty. But most scopes will make your object "vanish" at the slightest movement. All that hard work in tracking down your favorite planned will be for nothing. Well, not with the Meade LX200 ACF telescopes. These devices are equipped with Meade's amazing unique Zero Image Shift Microfocuser and Primary Mirror Lock technologies. What that allows you to do is, using a conveniently located lock knob feature, to lock the primary mirror of the scope in place, thereby practically "trapping" the image within your focus.
But sometimes, especially after long observation, you may tire and the scope might tremble a bit. Most conventional scopes will lose sight of image. However, sot so in the case of a Meade LX-00 ACF 14 inch computerized telescope. Once again, Meade has thought of a solution for this very real situation. All Meade LX200 ACF telescopes come with Meade's unique Permanent Periodic Error Correction (PPEC) feature, known as the Smart Drive. It is a smart piece of technology that "learns" and "remembers" the movements of individual users of the Meade LX 200 ACF, and then automatically makes adjustments for periodic shifts in the image to reduce guiding correction errors. That way, once you sight an object, your Meade scope will remember where it is, even through slight inadvertent shifts and moves of the scope.
The Meade LX-200 ACF 14 inch computerized telescope uses a lot of technology in its design so as to make your backyard star gazing parties fun events. For example, it comes equipped with a 16-channel Sony GPS receiver with plenty of intelligence built into it, so you don't have to waste endless hours aligning your Meade LX200 ACF scope to the exact coordinates of a planetary object. The GPS sensor will automatically capture ultra-precise coordinates, such as date, time and geo-location, and help to accurately and quickly align the Meade LX200 ACF telescopes to their precise destinations. Look Ma, no hands!
The GPS feature works in tandem with one of the Meade LX200 ACF telescopes neatest features that both seasoned and novice astronomers love. And that's the Meade AutoStar II. If you have ever used a GPS to navigate to an earthly destination, think of the AutoStar as a tool that will navigate you to over 145,000 heavenly destinations. Meade AutoStar II is a flash memory-based, software driven database of coordinates for celestial objects that you can view using your Meade LX-200 ACF 14 inch computerized telescope. To impress the guests at your Star gazing parties, all you need to do is ask someone to pick one of the 145,000 objects from the database and presto! Your Meade LX 200 ACF will take them right to the object.
And that's not all. You can download free updates and upgrades to the software and its database from the Meade website. So the next time a comet is due to pass over the earth, update your Meade AutoStar II software, set out your Meade LX 200 ACF in your backyard, select the comet from the "Hot Key" option, and watch your scope automatically position to the comet. If that won't impress your guests, then nothing will!
LX200-ACF Advanced Coma-Free Optical Tube Assemblies
|An important optional feature to optimize the performance of your Meade telescope. Image brightness in a telescope is crucially dependent on the reflectivity of the telescope's mirrors and on the transmission of its lenses. Neither of these processes, mirror-reflectivity or lens-transmission, is, however, perfect; light loss occurs in each instance where light is reflected or transmitted. Uncoated glass, for example, reflects about 4% of the light impacting it; in the case of an uncoated lens 4% of the light is lost at entrance to and at exit from the lens, for a total light loss of about 8%.|
Early reflecting telescopes of the 1700's and 1800's suffered greatly from mirrors of poor reflectivity- reflection losses of 50% or more were not uncommon. Later, silvered mirrors improved reflectivity, but at high cost and with poor durability. Modern optical coatings have succeeded in reducing mirror-reflection and lens-transmission losses to acceptable levels at reasonable cost.
Meade Standard Coatings: The optical surfaces of all Meade telescopes include high-grade optical coatings fully consistent in quality with the precision of the optical surfaces themselves. These standard-equipment coatings include mirror surfaces of highly purified aluminum, vacuum-deposited at high temperature and overcoated with silicon monoxide (SiO), and correcting lenses coated on both sides for high light transmission with magnesium fluoride (MgF2). Meade standard mirror and lens coatings equal or exceed the reflectivity and transmission, respectively, of virtually any optical coatings currently offered in the commercial telescope industry.
The Meade UHTC Group: Technologies recently developed at the Meade Irvine coatings facility, however, including installation of some of the largest and most advanced vacuum coating instrumentation currently available, have permitted the vacuum-deposition of a series of exotic optical coatings precisely tuned to optimize the visual, photographic, and CCD imaging performance of Meade telescopes. These specialized, and extremely advantageous, coatings are offered here as the Meade Ultra-High Transmission Coatings (UHTC) group, a coatings group available optionally on many Meade telescope models.
In Meade catadioptric, or mirror-lens, telescopes (including the ETX-90EC, ETX-105EC and ETX-125EC; LX10, LX90, and LX200GPS Schmidt-Cassegrains; and LXD55-Series Schmidt-Newtonians) before incoming light is brought to a focus, it passes through, or is reflected by, four optical surfaces: the front surface of the correcting lens, the rear surface of the correcting lens, the primary mirror, and the secondary mirror. Each of these four surfaces results in some loss of light, with the level of loss being dependent on the chemistry of each surface's optical coatings and on the wavelength of light. (Standard aluminum mirror coatings, for example, typically have their highest reflectivity in the yellow region of the visual spectrum, at a wavelength of about 580nm.)
Mirror Coatings: Meade ETX, Schmidt-Cassegrain, and Schmidt-Newtonian telescopes equipped with the Ultra-High Transmission Coatings group include primary and secondary mirrors coated with aluminum enhanced with a complex stack of multi-layer coatings of titanium dioxide (TiO2) and silicon dioxide (SiO2). The thickness of each coating layer precisely controlled to within +/-1% of optimal thickness. The result is a dramatic increase in mirror reflectivity across the entire visible spectrum; at the important hydrogen-alpha wavelength of 656nm. - the predominant wavelength of emission nebulae - reflectivity is increased from 89% to over 97%.
Correcting Lens Coatings: Meade telescopes ordered with the UHTC group include, in addition, an exotic and tightly-controlled series of coatings on both sides of the correcting lens or correcting plate, coatings which include multiple layers of aluminum oxide (Al2O3), titanium dioxide (TiO2), and magnesium fluoride (MgF2). Per-surface light transmission of the correcting lens is thereby increased at the yellow wavelength of 580nm., for example, to 99.8%, versus a per-surface transmission of 98.7% for the standard coating.
The importance of the UHTC group becomes apparent when comparing total telescope light transmission, or throughput, caused by the multiplier, or compounding, effect of the four optical surfaces. With each optical surface contributing significantly to telescope light throughput, the effect of all four surfaces combined is indeed dramatic, as demonstrated by the graphs on the facing page, as well as by the table of the brightest nebular emission lines. At the H-alpha wavelength of 656nm., total transmission increases from 77% to 93%, an increase of 93/77 or 21% at all three nitrogen-III and sulfur-II wavelengths of 655nm. and 673nm.- prominent lines in certain galactic nuclei and in supernova remnanats such as the Crab Nebula- transmission increases by 21%; ; at the helium wavelengths of 588nm. and 469nm. - strong emission lines in hot planetary nebulae - total telescope transmission increases by 18% and 19%, respectively; at the two nitrogen II lines of 655nm. and 658nm. and at the sulfur II line of 673nm., transmission is increased by 21%. Averaged over the entire visible spectrum (450nm. to 700nm.), total light transmission to the telescope focus increases by about 20%.
Observing with the UHTC: Meade ETX, Schmidt-Cassegrain, and Schmidt-Newtonian telescopes equipped with the UHTC present dramatically enhanced detail on the full range of celestial objects - from emission and planetary nebulae such as M8, M20, and M57 to star clusters and galaxies such as M3, M13, and M101. Observations of the Moon and planets, since they are observed in reflected (white) sunlight, benefit in image brightness from the full spectrum of increased transmission. The overall effect of the UHTC is, as it relates to image brightness, to increase the telescope's effective aperture. Image brightness (i.e., the ability to see faint detail) of the Meade 10" LX200GPS is, for example, effectively increased by about one full inch of aperture.
|Emission Line||Wavelength (nm.)||Transmission: Standard Coatings (%)||Transmission: UHTC Group (%)||Increase*|
* The % increase is obtained by dividing the UHTC-transmission (column 4) by the standard coatings transmission (column 3).
Effects on CCD Imaging: While the human eye loses sensitivity to light beyond wavelengths of about 700nm., CCD imaging chips remain sensitive to about 750nm. and longer, wavelengths at which the reflectivity of an aluminum coating is near its lowpoint. Importantly, however, the UHTC's total light transmission at 750nm. is 83%, vs. 72% for standard coatings, an increase of 83/72, or 15%.
|Optical Design||Advanced Coma-Free (ACF) with UHTC|