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Celestron AstroMaster 90AZ Review: Is It Worth It?

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Welcome to my review of the Celestron AstroMaster 90AZ.

The Celestron AstroMaster is an amazing piece of equipment designed for beginners and intermediates mostly for casual astronomy.

With its 90mm (3.5”) aperture, this telescope collects 65% more light than its smaller sibling, the AstroMaster 70mm option.

In this review of the AstroMaster 90AZ, I’ll cover all the pros and cons and the telescope’s performance in detail. 

So if you’re considering buying this telescope then I highly recommend that you should read this review till the end so that you can decide for yourself if this is the perfect telescope for you or you should skip it altogether.

My Verdict

If you’re looking for a dual-purpose telescope appropriate for both terrestrial and celestial viewing, then the AstroMaster 90AZ is for you. The 90AZ is capable of giving correct views of land and sky. It produces bright, clear images of the Moon and planets. It is easy to see the moons of Jupiter and the rings of Saturn with this beginner-friendly telescope. However, for decent views of the deep-space objects like galaxies and nebulae, the 90mm aperture of this telescope is not sufficient we recommend the larger aperture and light gathering ability of the Newtonian reflectors.


  • Made with high-quality coated optics.
  • Observe targets with clarity, contrast, and detail.
  • Suitable for terrestrial as well as astronomical use.
  • Fast and simple setup.
  • Affordable and suitable for lunar & planetary viewing.


  • The mount is not as smooth as it could be.
  • Not suitable for astrophotography.
  • Small aperture.

Celestron AstroMaster 90AZ Review

Refractor telescopes are one of the most revered optical designs in the telescope industry, but they’re a bit more expensive than their reflector counterparts. Well, the AstroMaster 90AZ combines a refractor telescope with a manual AZ mount in an inexpensive package ready for lunar and planetary observation for amateur and aspiring astronomers.

Optical Performance

The AstroMaster 90AZ is one of the mid-size refractors in the AstroMaster series. As a refractor, it has closed optics, collimation is rarely needed (if at all), and it has good contrast. 

With a slow focal ratio of f/11, it produces bright and crisp images of the moon and the planets making it one of the best telescopes for beginners on a budget looking for a refractor. 

The scope has multi-coated optics and the larger aperture allows for a more light grasp than its smaller refractor alternatives.

The telescope comes with 20mm and 10mm eyepieces that provide you with 50x and 100x magnification respectively. 

This feels sensible for a 3.5″ scope, but you will benefit from additional lenses in the long run – just don’t try to push this scope to 200x magnification as the images will begin to appear blurry.

Although the aperture is on the small side at 3.5”, but as a refractor, it promises strong resolution and crisp images with some compromise on color fidelity.

What Can You See With The AstroMaster 90AZ?

The AstroMaster 90AZ is best suited to view the moon and planets in great detail.

You can see that Jupiter’s storm clouds and The Great Red Spot, including the 4 Galilean Moon’s

You can also see the Saturn and its rings, and with a decent eyepiece or a Barlow lens, you can also see the surface details of Mars.

AstroMaster 90AZ really shines when it comes to the moon. The Moon looks spectacular with this telescope

For this price, there is no other model that can provide a better view of the Moon. The mountain ranges and craters look gorgeous, with little color defects.

This telescope is not powerful enough to produce decent good images of the DSOs. 

However, you can still get good images of brighter Messier objects such as Pleiades Star Cluster and Orion Nebula

I also managed to get a good look at the Andromeda Galaxy (M31) and M27, the Dumbbell nebula.

Terrestrial Viewing

The AstroMaster 90AZ has multi-coated optics which deliver fantastic images of the moon and planets. 

And since this telescope has an erect image diagonal which makes the images appear on the right side up this telescope is perfect for terrestrial viewing as well. 

This means that you can also use this telescope during the daytime for spotting birds, viewing nature, looking at buildings or people.

You can also take it on your boat to look at ships, whales, or distant landmass.


The telescope is very well built. While the alt-azimuth mount is sturdy enough to support the telescope, there are a few niggles that could be ironed out. 

The mount does seem to spring back slightly whenever you make a small adjustment, so familiarizing yourself with the nuances of the mount will take some patience. 

Thankfully the telescope’s dovetail mount is threaded so you could mount it to a better tripod that is smoother and easier to use.

Overall, the mount doesn’t provide optimum stability, but it works fine. The tripod is reasonably stable and it doesn’t bring up any complaints.


The AstroMaster 90AZ is not meant for serious astrophotography, but you can take amateur shots of the moon and planets with a smartphone and adapter. 

You could use a webcam-style CCD camera for planetary imaging.

The 90mm aperture of this telescope is just not enough to produce clear images when it comes to astrophotography.

Also, the alt-az mount makes it very hard to track objects in the night sky to do some serious astrophotography.


The telescope doesn’t really come with too many accessories. 

 The 20mm and 10mm eyepieces provide 50x and 100x magnification respectively. The 20mm will be your low-power, wide-field eyepiece and the 10mm Kellner will be your high-power eyepiece. 

The red dot finder is a modest device that solely projects a red dot on a surface for aligning.

A 90-degree erect image diagonal is included with the AstroMaster 90AZ telescope. Its angled design is ideal for astronomical use, but it also provides the correct orientation for terrestrial viewing. 

This is a convenient feature for beginner users who may want to use the telescope as a spotting scope.


The mount is a plastic altazimuth and not very stable. This is not really a deal-breaker as most low-budget branded telescopes come with mediocre mounts.

Although its performance is “not bad” with deep space objects, but if viewing nebulas, galaxies, and star clusters are your priority then don’t buy this telescope.

This telescope is best for viewing the moon and the planets.


The Celestron Astro Master 90AZ is one of the best refractor telescopes for beginners available in the market today. The aperture is not too bad it will not disappoint in the detailed views of land and wildlife, as well as the Solar System. 

It comes at a very competitive price. Overall, Celestron’s AstroMaster 90AZ is an excellent pick for beginners and slightly more seasoned stargazers alike.

I can assure you that with good care, some know-how about telescopes, and possibly some better eyepieces, the AstroMaster 90AZ will perform better than expected.

Written by:
Picture of Jason Parnell
Jason Parnell

At 15, I sold my bike to buy my first telescope. I spent the next 3 years sketching as many Messier objects as I could find from my garden, then at the age of 18, I discovered beer. I have wandered through California's Mojave Desert with other amateur astronomers in search of the best stargazing experience.

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We are a team of active amateur astronomers, here to help you with all your astronomy and science related needs – this is anything, from reviewing the latest telescopes to be released to talking about gravity and neurons. The Big Bang Optics was started because of our love for astronomy and to help others like us find the best telescope and accessories.


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