A computer-controlled 8-inch Schmidt-Cassegrain Telescope (SCT) remains one of the most popular choices for amateur astronomers looking for a do-it-all telescope near the $2000 price point. This aperture is enough to look at deep sky objects, enough focal length to look at the moon and planets, and – when properly equipped – can do astrophotography, all under the guide of a helpful computer.
Above: Meade’s 8inch LX90 Schmidt-Cassegrain telescope. This sample contains an upgraded visual back and diagonal. Photo by author.
Among 8-inch SCTs, Meade Instruments’ LX90 is one of the most popular models on the market. Originally introduced as a lower-cost alternative to their flagship LX200 series, the LX90 has received enough upgrades through the years that it now merits consideration for serious amateur astronomers, while saving $800 compared with the LX200. Early (ca. 2005) LX90 telescopes lacked many features, but the newest versions of the LX90 have GPS, higher-transmission UHTC coatings, and Meade’s new ACF (Advanced Coma-Free) optics package. The LX200 models still have heavier fork mounts, a slightly different controller, and are said to have upgraded encoders for better accuracy.
There are three models in the LX90 lineup – the 8-inch (reviewed here), the 10-inch, and the 12-inch. Setting up the scope is easier these days due to the built-in GPS. No longer does the user need to input time, date, and location. After turning the unit on, the telescope automatically obtains a GPS fix. Then, the user enters one of the alignment modes; the author always used the default two-star align. With practice, the user can obtain an alignment within a few minutes. After that point, the sky is your playground.
Another LX90 feature is the “Audiostar” hand controller. Not only will the telescope move automatically to celestial objects, it will give a brief audio lecture (sometimes even including practical observing hints) on selected targets. One foggy night, the optics dewed over, making observing impossible. But the author stayed outside in the fog, pointing the telescope to random objects in the sky, just to hear what the Audiostar would say. Some of the lectures are quite involved – make the telescope point at the moon, for instance, and be prepared to get a long narrative! The Audiostar has information on a variety of popular deep sky objects; once “below” a certain threshold, it defaults to a canned statement. Do note the audio can be turned off if desired.
SCTs are ideal for taking images of the planets and the moon. Many of the world’s master planetary and lunar imagers use stock, off-the-shelf SCTs. At the time of this review, Mars is receding and getting smaller, but the author obtained this image on Dec 27, 2020.
Here is the crater Gassendi, a few days before the full moon.
Drawbacks? The most common complaint about these telescopes usually concerns their pointing accuracy. The computer may not always place the object in the center of the eyepiece, all of the time. This can vary based on the thoroughness of the user’s initial alignment, the magnification used, and the user’s expectations. The accuracy on this sample (obtained on loan from a club member) was very good. Also, the author found Meade’s menu system in need of an update. Submenu item lists are not alphabetized as they are in those in competing models, and there are some curious decisions (“black holes” appears in the “deep sky” menu, for instance). Most of this can be fixed via future firmware updates.
If you’re shopping for a jack-of-all-trades telescope in the $2,000 price range, Meade’s 8-inch LX90 SCT should be on your list of candidates.
For more on the Meade 8” LX90 Schmidt-Cassegrain Telescope, including a demonstration of a sample 2-star alignment procedure, see the author’s YouTube video: