Celestron c90 Review: Best Spotting Scope For Target Shooting

Celestron is a well-renowned brand in the spotting scope market. They are known to provide some of the best all-rounder spotting scope. Why all-rounder? Because they can be used for digiscoping, astronomy, and your regular birding. The c90 is no different.

Celestron C90: Outlooks

Celestron C90

Specifications | Magnification: 39x; Objective Lens: 90 mm; Eye Relief: 20 mm; Exit Pupil: 2.3 mm; Linear FOV @1000 yds: 68 ft; Focal Length: 1250 mm; Weight: 74 Oz.

A Little History Lesson

The Celestron c90 is a Maksutov-Cassegrain. An optic designed by a soviet engineer named Dmitry Dmitrievich Maksutov. This design uses a fast spherical primary mirror and it has a mirror with a corrector lens at the front. 

Optics & Prism Quality

The optics are multi-coated. The Celestron c90 uses a BaK4 prism. In case you didn’t know, BaK4 prism is a high-end glass that is used in prism to make the overall scope a better one.

BaK4 has incredible potential to gather light and give the absolute best possible picture it can. Even though Celestron C90 is not even a 200$ spotting scope it still uses Bak4 prism glass.

There is no official disclosure about the prism coating so we can’t help regarding that. The objective lens is a huge 90mm one. You can do astronomy with it too. 

The 8×21 Erect Image Finder

It’s the tiny telescope that’s mounted on top of the C90. It’s a common feature in almost all catadioptric telescopes. This tiny scope has 8x power and a 21mm objective lens. 

The internal prism of this tiny scope makes sure that you see the image the same way your eyes do. Right side up and left to right. 

You may be wondering what job does this little gadget does. Most of the time they are low powered and low-resolution scope with a crosshair that enables a wide field of view.

The crosshair helps to center the target better. So, you can switch to the original scope and see the target in detail. 


If you haven’t noticed already, there is no magnification related information in the specifications chart. Why is that? Because all catadioptric scope comes with an interchangeable eyepiece.

What it means is, you can change the eyepiece to whatever zoom you want or no zoom at all. The options are infinite. 

But one thing that you should be wary of is that with high magnification it comes with a cost. It may have distortion and narrow field of view. So, don’t go overboard while buying an eyepiece.

The included eyepiece has 39x magnification. It has a narrow field of view 68 ft at 1000 yards. If you want a wide field of view we suggest you to buy a third party eyepiece for the scope.

Some Noteworthy Features

  • It comes with a 32 mm eyepiece. Of course, you can change it.
  • 8×21 erect image finder. 
  • Built-in SLR camera mounting. 
  • It can be used as both terrestrial and celestial.
  • Celestron gives a limited lifetime warranty.
  • Angular eyepiece. At 45 degree angle, the eyepiece is not uncomfortable to look through at all. 

What Kind Of Spotting Scope Is The C90 Mak?

When you look at the images of the scope you can tell it’s different than your regular spotting scopes. It’s a little bulky and larger than the modern compact spotting scopes. That’s because it falls into the category of catadioptric telescopes. It can be used for both terrestrial and celestial viewing. 


  • Excellent pricing.
  • Digiscoping possible.
  • It can be used to do astronomy.
  • Interchangeable eyepiece.
  • Built-in T adapter.
  • 8×21 finderscope available.


  • Not waterproof.
  • Not nitrogen filled.
  • The included tripod is useless.
  • Included eyepiece has a narrow field of view.

Celestron C90 Review Summary

With that price and the features it packs the Celestron c90 is quite an excellent purchase. You can do all the stuff you want to do with a spotting scope.

Watching terrain from a mountain top, watching the stars at a starry night or perhaps taking pictures through DSLR or a mobile phone AKA digiscoping. For the price you are paying this is an absolute steal deal.

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