Sky-Watcher Skymax-90 (OTA) - 90mm f/13.9 Maksutov-Cassegrain

Sky-Watcher SkyMax-90 (OTA): The pocket-sized planet telescope

The Sky-Watcher SkyMax-90 is a 90mm aperture, 1250mm focal length (f/13.9) Maksutov-Cassegrain in a tube that fits in almost any bag. This is the optical tube assembly (OTA) only, without a mount: you can place it on your own mount or via the camera tripod adapter onto a sturdy photo tripod. Maximum planetary sharpness per euro and per kilogram.

What do you see through the SkyMax-90?

The moon shows razor-sharp craters, mountain ranges, and play of shadows. Jupiter displays its cloud bands, Saturn its rings, and Venus its phases. Double stars are split surprisingly well for their size with this optics. Bright deep-sky objects like the Orion Nebula are also possible, but the narrow field of view makes planets and the moon its true specialty.

Loose tubing: your mounting, your choice

The OTA version is for those who already have a mount or want to travel light. Thanks to the standard tripod adapter, it also works on a sturdy tripod for lunar, planetary, and daytime nature observation. The 1.25-inch connection with a 90-degree star diagonal makes comfortable viewing immediately possible.

This is how to get the most out of this telescope

• Give the thick correction lens cooling time: 30 to 45 minutes outside before looking at high magnification. A Maksutov rewards patience with a rock-steady image.
• Protect against dew The front-mounted meniscus lens fogs up faster than a mirror. A dew shield is the most useful first upgrade for this type of telescope.
• Virtually maintenance-free The closed tube keeps dust out and collimation is rarely an issue. Set it down and look.
• Magnification: The 10 mm eyepiece already provides 125x magnification; exactly what this optics are made for. Adding more magnification rarely makes sense in the Dutch climate.
• Plan with the moon: Around the first quarter you see the most detail along the terminator. Our lunar calendar have the best nights in a row.

For whom yes and for whom no

Hello moon and planet watchers, city and balcony observers (bright targets are less affected by light pollution), and travelers who want a short, maintenance-free tube. Still unsure about the type? Our Telescope Buying Guide for Beginners List the considerations.

Not For wide deep-sky fields, the field of view of this long focal length is too narrow; a short Newton would be a better fit. If you want a complete set with a mount, consider the SkyMax-90 EQ1 or one of the 102 bundles. Long exposure astrophotography is suited for the smart telescopes; moon photos with a smartphone adapter are actually a strong point on a Maksutov.

Featured accessories

These accessories add the most after purchase:

• Moon Filter 25%: at this long focal length, the moon is the main course, and bright. The Omegon Moon Filter 25% (1.25 inches) dims the light and increases the contrast. More explanation in our Moon filter guide.
• Smartphone adapter: It’s precisely with a Maksutov, with its long brand focal length, that moon photos taken with a phone are impressive. The Sky-Watcher SmartPhoto+ adapter comes with a special 20 mm photo eyepiece.
• Carrier bag The short tube calls for a compact bag. Check out the carrier bags and choose the size that fits.

Technical specifications

Included in the box

• Sky-Watcher SkyMax-90 Optical Tube Assembly (OTA, telescope only)
• Eyepieces: 25 mm, 10 mm (1.25″)
• Viewfinder: red dot finder

Honest advice from observers

We sell and use the Sky-Watcher line ourselves. In our Sky-Watcher merk Guide We'll explain which series are strong and which you'd rather skip. View the full range on our Sky-Watcher merk Page. Order before 11:59 PM for fast delivery, in the Netherlands and Belgium.