Meade ETX90 Observer 3.5" go-to Maksutov, tripod, case, and Audiostar computer


Availability: More on the way

The fully go-to computerized ETX90 Observer portable observatory has computer-optimized UHTC multicoated 90mm Maksutov-Cassegrain optics, AudioStar computer control, tripod, tripod carry bag, scope hard case, and two eyepieces - all at a remarkably sensible price.
Our Product #: M90ETX
Meade Product #: 205004

Product Description

The fully go-to computerized Meade ETX90 Observer is designed to be the ideal ultra-portable telescope. It combines Meade's unsurpassed optics with industry-leading electronics to deliver a truly exceptional viewing experience. The computer-optimized Maksutov-Cassegrain optics of the Meade ETX90 Observer yield remarkable high power lunar, planetary, star cluster, and binary star images.

The ETX90 Observer's standard equipment AudioStar computer hand control is amazingly simple to operate. It will even help you align the scope on the sky. You don't have to know Castor from Pollux, or Albireo from Zubeneschamali. All you have to do is tell the AudioStar where and when you are on Earth, level the tube, and show it where North is located using the supplied bubble level/compass. The AudioStar computer will do the rest.

The Meade ETX90 Observer's Optical System . . .

Maksutov-Cassegrain optical tube: 90mm (3.5") aperture, 1250mm focal length, f/13.8 focal ratio. Removable optical tube has a Vixen-style dovetail with a 1/4"/20 thread mounting hole for using the optical tube on a standard photo tripod as a terrestrial spotting scope.

Fully multicoated optics: Anti-reflection UHTC (Ultra High Transmission Coatings) multicoatings on both sides of the Maksutov corrector lens, plus high light transmission enhanced aluminum multicoatings on the mirrors, provide a 16% increase in light throughput compared to standard coatings. UHTC multicoatings effectively add the equivalent of more than a quarter of an inch of extra light-gathering aperture to the performance of a scope with standard coatings, but at no increase in size or weight.

Dust covers: Dust covers protect the meniscus corrector lens and seal the Cassegrain focus on the rear cell.

Finderscope: The supplied straight-through non-magnifying illuminated red dot finder seems to projects a red dot of light on the sky or terrestrial background for astronomical alignment purposes and to help aim the scope when the optical tube is used as a terrestrial spotting scope.

Star diagonal: Built-in first surface flip-mirror. For astronomical observing, the internal flip-mirror directs the image to the eyepiece holder at the top of the scope. Touch a lever, and the flip-mirror redirects the image through the Cassegrain focus at the rear of the scope to an optional #64 T-adapter and T-ring for lunar or terrestrial photography.

Two eyepieces: One is a 1.25" 26mm Super Plössl (48x). The eyepiece field of view is 1.04 degrees, more than twice the diameter of the full moon. The second eyepiece is a higher power 1.25" 9.7mm Super Plössl (129x) for close-up lunar, planetary, binary star, and globular star cluster views.

The Meade ETX90 Observer's Mechanics and Electronics . . .

Dual fork arm altazimuth mount: The removable optical tube is aluminum. The rear cell, fork arms, and drive base are durable metal-reinforced injection-molded plastic that helps keep the cost of the Meade ETX90 Observer so very reasonable.

There are three rubber feet on the base of the scope. These allow the ETX90 Observer to be placed on a suitably sturdy tabletop or flat surface for casual computerized observing without having to set up the supplied full length field tripod.

The mount includes built-in right ascension and declination DC drive motors for tracking objects under the control of the supplied AudioStar computer. The motors are powered for up to 20 hours by six AA batteries (not supplied) in a battery holder that fits into an internal battery compartment in the telescope base. A 9V~12V DC input jack will let you plug in an optional AC or DC adapter to power the scope from household AC or a rechargeable battery pack.

When used in the default altazimuth mode, the supplied AudioStar computer hand control moves the scope in any of four directions (right/left and up/down) at any of nine speeds. The speeds range from 2x the sidereal rate for guiding, up to 5 degrees per second for locating objects and slewing, plus the sidereal rate for tracking objects. No manual slow motion controls are provided - or needed - as pushbuttons on the AudioStar hand control will do all the powered slewing and centering you might want. When set up on the supplied tripod for equatorial (polar) operation using the tripod's built-in equatorial wedge, the AudioStar computer converts the right/left, up/down altazimuth directions to motions in right ascension and declination to correspond with the coordinates of objects on the celestial sphere.

AudioStar computer hand control: The supplied #497 AudioStar computer automatically slews to, and tracks, more than 30,000 near and deep space objects (although not all will be visible due to the 11.7 limiting magnitude of the scope's 3.5" aperture). The objects include all 110 of the Messier objects; the complete 5386-object IC catalog, the complete 7840-object NGC catalog, the complete 109 object Caldwell catalog of the best objects for small telescopes; 16,800 stars from the SAO catalog including double starts, variable stars, and other stars of special note; the planets; 26 of the brightest asteroids; 15 periodic comets; 50 earth-orbiting satellites; the centroids of all 88 constellations; plus user-defined objects and guided tours around the sky.

The AudioStar can show you these objects the very first night you use your scope - even if you've never used a telescope before! And a speaker built into the computer hand control lets the unique Astronomer Inside software provide you with more than four hours of fascinating audio descriptions of the objects you are observing. Astronomer Inside puts the experience and astronomical knowledge of a professional astronomer in the palm of your hand.

The AudioStar includes a dual-axis drive corrector with PEC (Periodic Error Correction). This allows long-exposure guided DSLR or CCD astrophotography in a polar mode, using the equatorial wedge built into the supplied steel tripod.

The AudioStar 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.

Adjustable height tripod and tripod carry bag: The supplied full-length field tripod provides a rigid mounting platform for virtually any observing application, astronomical or terrestrial, and can be used for either standing or seated observing. The tripod has tubular steel legs and is adjustable in height from 26" to 44" when used in the altazimuth mode.

The tripod has a built-in equatorial wedge with an integral latitude scale and no-tool latitude (altitude) adjustment for use at any observing latitude between 20° and 90°. The 90° (altazimuth) position is for terrestrial observation and for quick set-up astronomical observing. Setting the wedge tilt plate to your observing latitude and aligning the scope on the celestial pole allows more accurate object location and sidereal rate tracking, but takes a little more time to set up.

The ETX90 Observer drive base attaches to the tripod in seconds using two thumbscrews in the wedge tilt plate. The thumbscrews are tethered and spring-loaded so they can't be lost in the field. The spreader bar that holds the legs open is spring-loaded as well, so setting up and taking down the tripod takes only a few seconds. A soft carry bag is provided to transport the tripod.

Hard case for scope: A locking hard case with carry handle is provided to transport and protect the ETX90 Observer scope itself.

Tech Details

Aperture 3.5"
Binary and Star Cluster Observation Good
Focal Length 1250mm
Focal Ratio f/13.89
Galaxy and Nebula Observation Fair
Heaviest Single Component 9.8 lbs.
Highest Useful Magnification 187x
Lunar Observation Very Good
Weight 18.9 lbs.
Planetary Observation Good
Resolution 1.3 arc seconds
Telescope Type Maksutov-Cassegrain
Visual Limiting Magnitude 11.7
Warranty 1 year


Review by:
Superb scope for planetary viewing. I have spent hours watching the jovian moons orbit Jupiter through this small, but powerful mak. Jupiter's banding is not only evident, but highly resolved. It is light enough to be an anytime telescope, yet powerful enough to provide highly resolved images for the serious observer. Meade really hit it out of the park with the ETX and I am so glad they brought it back. as a side note, Meade is one of the best manufacturers I have dealt with for issues or concerns, being prompt, helpful, and courteous. For the price, you won't find a better portable scope. (Posted on 10/10/2018)
Review by:
Great little telescope for the planets and moon! The included cases, Go To capability, and portability combined with the superb optics make this little scope a winner. This was the first computerized mount I ever used and although it can be tricky and a challenge at times, once you get it properly aligned, it's a real gem. The price at this time is a real bargain for all the accessories that were once extra when this little scope was first introduced years ago. I own 4 Meade telescopes and this is the one that started it all! (Posted on 10/6/2018)
How do you rate this product? *

Supplied Accessories