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Orion Telescopes
Orion StarMax 90 Mak-Cass Telescope & Planetary Kit
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  • This thorough telescope and accessory kit is outfitted for planetary viewing perfection at a value price
  • Long 1250mm focal length Maksutov-Cassegrain telescope with 90mm aperture provides plenty of magnification ability in a compact, tabletop package
  • Included Color Filter Set enhances landscape details and cloudy features on the bright visible planets
  • Included 7.5mm Sirius Plossl 1.25" eyepiece provides a high magnification view, with pleasing 52-degree apparent field-of-view
  • Included Shorty 2x Barlow Lens adds versatility by doubling the magnification of each eyepiece in your collection, also includes Starry Night astronomy software

Learn more
Item #  27166

Whoever coined the phrase "big things come in small packages", would have definitely applied that expression to our Orion StarMax 90 TableTop Maksutov-Cassegrain Telescope and Planetary Kit. This ultra-compact Maksutov-Cassegrain (Mak-Cass) gives surprisingly big views for an instrument of its modest size. It's a very capable introductory telescope which is also popular as a grab-and-go second telescope for more experienced astronomy enthusiasts.

The long, 1250mm (f/13.8) focal length gives the StarMax 90 TableTop some serious magnifying power - the included 25mm and 10mm 1.25" Super 3-element telescope eyepieces yield viewing powers of 50x and 125x, respectively. It collects over 25% more light than its GoScope 80 refractor cousin, and up to 225% more light than a typical beginning 60mm refractor telescope. With the StarMax 90 TableTop Mak-Cass, you'll enjoy crisp observations of planetary delights such as lunar landscapes, Saturn's rings and Jupiter's moons. As you scan the Milky Way, you'll also be able to pull in some open and globular star clusters, as well as a nebula or two.

The optical tube assembly of the StarMax 90mm TableTop Maksutov-Cassegrain Telescope and Planetary Kit is attached to a stable swivel base, via a quick-release dovetail mount with adjustable altitude tension. The telescope tube can easily be removed from the base and mounted on an optional photo tripod (sold separately). The small swivel base itself can also be mounted on a camera tripod with a 3/8" or 1/4"-20 threaded post, thanks to a threaded acceptor on the bottom of the base and a handy included adapter.

A red-dot reflex sight, smooth-adjusting internal focuser (which moves the primary lens back and forth) and included 90 star diagonal round out the standard features of this compact, yet surprisingly capable, Maksutov-Cassegrain telescope.

This value-packed version of our StarMax TableTop includes the Orion Planetary Explorer Kit which comes with multiple items to enhance your views of Earth's neighbors in the solar system. Most of the planets are nice and bright when visible in the sky, making them wonderful targets to train your telescope on. Make the most out of planetary viewing sessions with the included Orion Set of Four Color Telescope Filters, 7.5mm Orion Sirius Plossl telescope eyepiece, Orion Shorty 2x Barlow Lens, and the Orion Beginning Stargazers Toolkit.

Because many planets have a characteristic color (for example, Mars is reddish), a color eyepiece filter will reduce the predominant hues to enhance contrast and uncover otherwise hidden planetary markings. That's why "the Red Planet" is most effectively enhanced with a green filter! The 1.25" Set of Four Orion Color Telescope Filters includes a foam-lined hard case that conveniently holds all four filters. Here's a bit more specific information on each of the four included filters, and how they can help improve planetary and lunar views through the Orion StarMax 90 Mak-Cass Telescope:

#15 Deep Yellow Planetary Filter

  • Enhances red and orange features on Saturn, Jupiter, and Mars
  • Makes low-contrast cloud detail on Venus more visible

#25 Red Planetary Filter

  • Reveals martian surface details in large telescopes
  • Enhances bluish cloud regions on Jupiter and Saturn
  • Increases contrast of Mercury against blue sky
  • Optimizes cloud definition on Venus

#58 Green Planetary Filter

  • Enhances contrast of blue and red structures on Jupiter (including Red Spot)
  • Makes melt lines around Martian polar ice caps more visible
  • Saturn's subtle cloud belts become visible with good seeing conditions

#80A Medium Blue Planetary Filter

  • Helps to reveal details in Jupiter's equatorial cloud belts and Red Spot
  • Makes high clouds and polar caps on Mars visible
  • Lunar surface details will pop out with this eyepiece filter
  • Venusian cloud features are more detectable

Offering a wide 52 apparent field of view, the 7.5mm Orion Sirius Plossl Telescope Eyepiece included in this value-packed package provides extremely sharp images with impressively high contrast. It's ideal for all types of telescopes: reflector, refractor, and catadioptrics like the StarMax 90 TableTop Maksutov-Cassegrain. The Plossl 4-element design is renowned for its outstanding performance, and has become the standard by which all other telescope eyepieces are judged. The 7.5mm Orion Sirius Plossl telescope eyepiece is superb for high-power planetary and lunar observation, and is well suited to double-star viewing when stable seeing conditions permit.

A 2-power (2x) Barlow lens, like the included Orion Shorty 2x Barlow, is an extremely versatile eyepiece accessory that doubles the magnification of any telescope eyepiece its used with. For example, when using the StarMax 90mm Tabletop Mak-Cass with its 1250mm focal length, using a 7.5mm eyepiece will yield a view with 166.7-power magnification (1250 divided by 7.5). If you installed the same 7.5mm eyepiece into the Shorty 2x Barlow Lens and then ionserted into the telescope, your viewing magnification would be increased to 333.4-power magnification (166.7 x 2). What's more, the Orion Shorty 2x Barlow gets it's "Shorty" moniker from its compact size compared to other Barlow lenses, so it's easier to find a spot for it when packing your gear for a night under the stars.

The included Orion MoonMap 260 is a useful reference map of the Moon's surface that will help the whole family learn the names and locations of more than 260 craters, mountains, valleys, "seas" and other interesting lunar features you can explore with your telescope. Use the MoonMap 260 to identify craters you've observed, or use it before you go out with a telescope to plan a night full of Moon-watching family fun.

Meets or exceeds all California State Environmental Quality & Safety Regulations (CARB 93120 Phase 2 Compliant).


Limited Warranty against defects in materials or workmanship for one year from date of purchase. This warranty is for the benefit of the original retail purchaser only. For complete warranty details contact us at 800-676-1343.


Please note this product was not designed or intended by the manufacturer for use by a child 12 years of age or younger.

Product Support
Visit our product support section for instruction manuals and more
  • Best for viewing
    Lunar & planetary
  • Best for imaging
    Lunar & planetary
  • User level
  • Optical design
  • Optical diameter
  • Focal length
  • Focal ratio
  • Optics type
  • Eyepieces
    3-Element 25.0mm,10.0mm (1.25")
  • Magnification with included eyepieces
    50x, 125x
  • Resolving power
  • Lowest useful magnification
  • Highest useful magnification
  • Highest theoretical magnification
  • Limiting stellar magnitude
  • Optical quality
    Diffraction limited
  • Finder scope
    EZ Finder II
  • Focuser
  • Diagonal degrees
    1.25" 90° Prism Star
  • Secondary mirror obstruction
  • Secondary mirror obstruction by area
  • Mount type
  • Polar-axis scope
    Not available
  • Tube material
  • Tripod material
  • Length of optical tube
    10.0 in.
  • Weight, optical tube
    3.7 lbs.
  • Weight, mount/tripod
    2.8 lbs.
  • Weight, fully assembled
    6.5 lbs.
  • Warranty
    One year

Orion StarMax 90 TableTop Maksutov-Cassegrain Telescope
90 star diagonal
25mm telescope eyepiece
10mm telescope eyepiece
EZ Finder II reflex sight
3/8-inch -to-1/4"-20 threaded adapter for tripod attachment
Orion Set of Four Color Filters
Orion 1.25-inch 7.5mm Sirius Plossl eyepiece
Orion 1.25-inch Shorty 2x Barlow Lens  
Orion Beginning Stargazers Toolkit

Orders received by 1pm Eastern Standard Time for in-stock item the same business day. Order received after noon will ship the next business day. When an item is not in-stock we will ship it as soon as it becomes available. Typically in-stock items will ship first and backordered items will follow as soon as they are available. You have the option in check out to request that your order ship complete, if you'd prefer.

A per-item shipping charge (in addition to the standard shipping and handling charge) applies to this product due to its size and weight. This charge varies based on the shipping method.

Standard Delivery: $0.00
Standard Delivery to Canada: $5.00
3 Day Delivery: $15.00
2 Day Delivery: $15.00
Next Day Delivery: $21.00

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