Celestron 90 Maksutov-Cassegrain Spotting Scope Review

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Many people love going outdoors. They say seeing and experiencing nature is always good for the soul. In fact, many individuals love the outdoors so much that they are willing to invest in a tool that would help them appreciate the sceneries even from afar. Luckily, there are plenty of spotting scopes on the market for this purpose.


If you are on the lookout for one, then you may want to consider the Celestron C90 Maksutov-Cassegrain Spotting Scope. Just how exactly does it fare?

Product Overview

The Celestron C90 Maksutov-Cassegrain Spotting Scope promises to be the perfect companion for outdoor trips. It boasts of being versatile, easy to use, and highly portable.


This spotting scope has 39 times magnification and Maksutov-Cassegrain optical design, which uses convex meniscus lenses for correction and avoidance of collimation. It has an eyepiece that is 32mm Plossl and a field of view of 1.3-degrees and 67 feet at 1000 yards. The lens is multi-coated, which is the best lens for a spotting scope. The item also has a 15-feet close focus distance and 20 mm eye relief. It has a folding eyecup complete with the eyepiece.


One can easily locate its subject with this tool’s 8 mm x 21 mm erect image finderscope. This unit also is compatible with a wide range of 1.25-inch mount eyepieces so that users can have more magnification. It boasts of having a highly versatile design that is portable and easy to use. Plus, it comes with a T-mount adapter that is built-in and easily lets the user connect their DSLR camera bodies to put together a 1250 mm lens.


The spotting scope also has a dovetail rail as well as a 1/4-20 threaded mounting, which makes it easy to mount on either astronomical or camera tripods. The item weighs 5.07 pounds and measures 16 inches x 7 inches x 10 inches.


However, just like with any product, this spotting scope by Celestron has its flaws. Its weight and size require a heavy tripod, which makes the travel and viewing experience a bit challenging. This scope also has a low contrast image as well as eye relief. The finder scope cannot be adjusted, too. Plus, users might be disappointed with its performance in a dark environment. This scope is neither waterproof nor fog proof.

What's Included

The C90 package includes the spotting scope, custom backpack case, T-mount adapter, a 32 mm eyepiece, 45-degree image diagonal, image finderscope, objective cover, cleaning cloth, and instruction manual.

The Pros and Cons


• Maksutov-Cassegrain optical design
• 39 times magnification
• Multi-coated lens
• Field of view of 1.3-degrees and 67 feet at 1,000 yards
• 15-feet close focus distance
• Eye relief of 20 mm
• Folding eyecup with the eyepiece
• 8 mm x 21 mm erect image finderscope
• Compatible with a wide range of 1.25-inch mount eyepieces
• Dovetail rail and a 1/4-20 threaded mounting
• Multiple accessories included


• Too heavy and bulky for a spotting scope
• Needs a heavily built tripod
• Poor eye relief
• Low contrast image
• Finder scope cannot be adjusted
• Does not work well in a dark environment
• Not waterproof or fog-proof


The Celestron C90 Maksutov-Cassegrain Spotting Scope has many competitors that offer highly similar features.

For example, the Orion 9825 Apex 127mm Maksutov-Cassegrain Telescope also uses the Maksutov-Cassegrain optical design and has a multi-coated lens as well.


The Orion 9825 Apex 127mm Maksutov-Cassegrain Telescope has a 25mm eye relief and 1.25-inch eyepiece. Its finder scope is 6×30, which is better than the product being reviewed. The eyepiece adapter has T-thread to allow for an attachment of a camera body measuring 35mm. The T-ring, however, must be bought separately. It also comes with a soft carry case and a starry night astronomy software. The product maker also offers a one-year limited warranty, which is not provided for by Celestra.


This spotting scope by Orion is bulkier and more cumbersome with its weight of 8.6 pounds and dimensions of 25 inches x 11.2 inches x 10.2 inches. It also shares the same flaw as the product in this review since it performs poorly in dark environments.

The Verdict

The Celestron C90 Maksutov-Cassegrain Spotting Scope promises a great viewing experience, ease of use, portability, and versatility. It uses the Maksutov-Cassegrain optical lens design just like many of the spotting scope in the market. Its lens, too are multi-coated, which is the best type of lens for spotting scopes. This product boasts of other virtues as well.


So, is this spotting scope worthy to buy? This would depend on the user’s preferences. If one wants a more lightweight spotting scope as well as an item that can work with the light tripods, then this product is not the best option. Plus, if being able to view clearly even in dark environments is non-negotiable, and if one is wearing a thick pair of eyeglasses, then this spotting scope is not the product to buy.


However, for those who do not plan to hike difficult terrains, use it in extreme weather and dark situation, and are not wearing thick eyeglasses, then this product might suit your needs.  Make sure to handle and maintain the item carefully as the product maker does not offer a warranty, and the item is neither weatherproof nor fog-proof.

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