Previously, we discussed about Celestron Advanced VX 8 and Nexstar 8SE. Now we’re going to discuss another telescope from Celestron. Unlike previous telescopes which are Schmidt-Cassegrain type, this time we’re going to compare two spotting telescope type from Celestron, the C90 and the C5. Spotting telescope is a small portable high-power telescope with added optics to present an upright image and optimized for observation of terrestrial objects but the ones from Celestron is specifically design to also view object outside the earth.

Celestron C90

Celestron C90 MAK with the Maksutov-Cassegrain optical design is highly versatile and widely-known for its portable design that is easy to use and has a variety of applications. Priced at $199.00, the Maksutov-Cassegrain design of the C90 uses a combination of mirrors and lenses. This optical system has a focal length of 1250mm in a body of only 12 inches long. The Maksutov design also carries high power views without a hint of the chromatic aberration, also called blue fringing, that can alter high power views in competing refractor style spotting scopes. It is capable of locating your subject quicky with the included 8×21 erect image finderscope. Additionally, the C90 uses astronomy eyepieces and accepts a wide range of 1.25” mount for even more magnification, it’s able to magnify up to 39x to clearly view your favorite sky objects. In the purchase of this telescope, a backpack case is included for more convenient way to bring and transport your scope. Equipped with lens built-in T-mount adapter threads, Celestron C90 allow easy connection of DSLR camera bodies to create a 1250 mm lens, it provides super-telephoto for your satisfaction. Designed with both a dovetail rail and a ¼-20 threaded mounting port, the C90 provides versatile mounting options. You can mount this telescope easily on both astronomical and camera tripods. Moreover, C90 comes with multiple accessories which are 32 mm eyepiece, 45° erect image diagonal, 8×21 mm erect image finderscope, objective cover, cleaning cloth, and instruction manual all included.

Product Dimensions16 x 7 x 10 inches13 x 6 x 10 inches
Shipping Weight4.62 pounds5.98 pounds
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Even without the eyepiece, the C90 provides great result at 40x magnification unlike other low-cost spotting scopes that give fuzzy images. The C90 uses the same 1.25 inches eyepieces used in astronomical telescopes. The standard equipment 32mm eyepiece yields a magnification of 39X, but many other eyepieces can be used to vary the magnification. The Celestron C90 are very well built, with sturdy materials and excellent multi-coatings visible on the front lens. For greater experience, if you use an optional 12.5mm eyepiece to look at Jupiter at 100x magnification, you can clearly see Jupiter’s major cloud formations as well as its four moons. Even for nearer objects like the Moon and stars, you can see more clearly image with the push of 200x magnification with an optional 6mm eyepiece. For daily use like watching birds in the backyard, the optical lens treats you to charming views full of lively color and sharp detail only with a close focus distance of only 15 feet, the detail and texture I see is simply amazing. If you want more magnification viewing, it requires a solid tripod and its heavy-duty Altazimuth Tripod comes with slow motion controls to allow the scope to be pointed precisely. The other drawback to high magnification viewing is a narrow field of view and high magnification makes it hard to follow moving targets like birds in flight. Overall, the Celestron C90 MAK does a fine job as a companion to good pair of binoculars. The C90 also doubles as a portable astronomy scope so you can carry it around everywhere to get view of thousands of craters on the Moon as well as showing the moons of Jupiter and the rings of Saturn.

Celestron C5

Three times more expensive than the previous C90, at $614.74, Celestron C5 has 5 inches (127 mm) aperture with 1250 mm f/10 Schmidt-Cassegrain optical system. Its optical quality, reliable, high quality spotting scope is the reason it was selected to travel aboard the Space Shuttle by NASA. The C5 spotting scope is an ideal choice for the serious bird watcher, nature lover or anyone who enjoys beautiful views either from your home or in the field. At just six pounds in weight and 11 inches in length, this spotting scope is a completely portable visual and photographic instrument that performs well in any viewing location. Furthermore, this telescope’s water white glass is coated with special proprietary StarBright XLT optical coatings to achieve up to 97.4% light transmission. The C5 accepts a wide range of 1.25” mount eyepieces for even more magnification and offer 4½ times more light gathering ability than a 60 mm spotting scope and 2½ times more than an 80 mm scope, Celestron’s C5 is the clear choice when a powerful instrument delivering brilliant, crisp views is what you require. The C5 spotting scope is a wonderfully versatile instrument, and its near focus of approximately 20 feet allows you to observe plant life, wildlife, birds or insects with ease. At the same time, the C5 can also be used as an astronomical telescope.

C5 offers a wide variety of multiple accessories included to expand the capabilities of this special instrument. It comes with soft-sided case with fitted inserts, 25 mm eyepiece, 45° erect image diagonal, 6×30 mm erect image finderscope, objective cover, cleaning cloth, and instruction manual all included. The C5 aperture of 5 inches allows for a lot of light gathering ability for bright, detailed views even in dim viewing conditions, it easily outperforms smaller aperture spotting scopes. In addition, the C5 goes easily from working as a powerful spotting scope to being a high performance 1250 mm f/10 telephoto lens. Photography couldn’t be easier, because the C5 is designed to be fully camera adaptable. To take professional quality shots with the C5, just attach the correct optional T- Adapter and T-Ring for your 35 mm SLR camera to the back of the C5 spotting scope, and you’re ready to shoot. The tripod adapter block on the C5’s tube makes easy work of mounting the instrument onto a tripod for either viewing or photography. Thanks to its integrated T-mount threads, the C5 works as a powerful spotting scope or a high-performance 1250 mm f/10 telephoto lens for your DSLR. Versatile Mounting Options Designed with both a dovetail rail and a ¼-20 threaded mounting port, the C5 mounts easily on both astronomical and photographic tripods. Read also: CELESTRON C5 Vs SKYWATCHER MAK 127.


- Multilayer optics.
- Maksutov-Cassegrain Optical Design.
- Compact and portable design.
- Erect imaging system for terrestrial and astronomical use.
- Schmidt-Cassegrain 5 '' optical design.
- XLT StarBright Coatings
- 0.984 in (50x) eyepiece.
- Erect image 45 ° diagonally.


The C90 is a fine little telescope to play around with, it’s small and compact, you can carry it around everywhere. It’s optimal for nearer object and capable of delivering great images of the moon but if you want to see something, that starts at 4-inches of aperture, the C5 with its faster focal ratio and ability to use SCT accessories is better. C5 is able to provide much better and brighter deep sky and other planets. You can also get a wider field on the c5 with less vignetting than the C90. Both are about the same length and the C5 feels only a little heavier and more expensive so it’s better for people who already know astro-viewing. For beginners who likes adventures to places to see the night sky, C90 is much less costly, lighter, easier to mount on a small mount and deliver fine result but C5 is more recommended because its quality is much more amazing and it’s useful for long-term.

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