Celestron CGEM II 700 Maksutov-Cassegrain Telescope Review

How the Celestron CGEM II 700 Maksutov-Cassegrain Telescope Performed Under Pressure

As someone who’s spent a decade wrestling with gear in environments ranging from dusty workshops to unforgiving field conditions, I’ve learned to appreciate instruments that offer precision without fragility. My quest for a dedicated planetary and lunar observer led me to the Celestron CGEM II 700 Maksutov-Cassegrain Telescope, a specialized optic promising high-contrast views. The need arose from a desire to truly see the fine details on Jupiter and Saturn, something my wider-field scopes couldn’t quite resolve.

Upon unboxing, the initial impression was one of solid, considered engineering. The beige finish of the optical tube and the robust construction of the CGEM II mount exuded a sense of stability. It wasn’t the sleek, minimalist design of some modern scopes, but rather a functional, no-nonsense build that suggested it was designed for purpose, not just aesthetics. I had considered a smaller Schmidt-Cassegrain for portability, but the allure of the Maksutov’s inherently sharp optics for planetary detail was too strong to ignore. My first reaction was a quiet satisfaction, a feeling that I might have found the right tool for the job.

Real-World Testing: Putting Celestron CGEM II 700 Maksutov-Cassegrain Telescope to the Test

My initial testing ground for this optic was my own backyard, under the relatively light-polluted skies of a suburban area. Setting up the CGEM II mount with its tripod was a straightforward affair, even with the counterweights and optical tube. The telescope’s considerable focal length, a massive 2700mm, immediately dictated a slower approach to observing; focusing required a gentle touch. I found the included 8×50 finderscope to be an invaluable aid in locating targets, projecting a clear, wide field that made centering planets less of a chore.

Extended use, spanning several months and various observing sessions, revealed the true character of this Celestron instrument. The StarBright XLT coatings on the optics consistently delivered bright, sharp images, even when viewing dimmer deep-sky objects like globular clusters. I particularly appreciated the optical tube’s ability to accept 2-inch accessories, which opened up a world of wider-field eyepieces for those moments when I wanted a broader perspective. While the mount’s 40 lbs load capacity is ample for this tube, I did notice that even slight vibrations from nearby traffic could take a moment to settle, a common trait with equatorial mounts of this class. Cleaning was simple; a soft brush for the optics and a damp cloth for the tube and mount. Compared to lighter, alt-azimuth mounts I’ve used, the stability of the CGEM II was a welcome upgrade, though it demands a more deliberate setup.

First Use Experience

Setting up the Celestron CGEM II 700 Maksutov-Cassegrain Telescope for the first time was an exercise in methodical assembly. I focused my initial sessions on Jupiter and Saturn, as the product description highlighted its strengths in planetary viewing. The f/15 focal ratio meant that achieving higher magnifications, well into the advertised 67 – 420x range, was readily achievable. I was particularly struck by how sharp the images were, with the Maksutov design seemingly suppressing chromatic aberration effectively. A minor quirk I encountered was the slight stiffness in the declination slow-motion control initially, which smoothed out after a few movements.

Extended Use & Reliability

Over weeks of dedicated observation, the CGEM II 700 Mak proved to be a reliable performer. The low cog DC Servo motors with integrated optical encoders in the mount provided surprisingly smooth and accurate slewing, and tracking was generally excellent once polar aligned. I did notice a slight wobble when pushing the telescope to its absolute maximum magnification without perfect focusing, but for general planetary viewing in the 150x-250x range, it was remarkably stable. Maintenance has been minimal; keeping the optics clean and ensuring the mount’s gears are free of dust are the main concerns. This Celestron optic has held up admirably, far surpassing the performance of simpler, less robust scopes I’ve owned.

Breaking Down the Features of Celestron CGEM II 700 Maksutov-Cassegrain Telescope

Specifications

The Celestron CGEM II 700 Maksutov-Cassegrain Telescope boasts a formidable set of specifications designed for high-power viewing. Its core is the Maksutov-Cassegrain optical tube with an impressive 2700 mm focal length and a focal ratio of f/15. This extreme focal length, coupled with the 180 mm objective aperture, is what grants it the superior magnification and detail-gathering capabilities for planetary observation. The StarBright XLT optical coating is a key feature, maximizing light transmission for brighter, more contrasty images.

The included 8×50 straight-through finderscope is substantial, offering a wide field of view for locating celestial targets. The telescope comes with a 2-inch visual back and a 2-inch star diagonal with a 1.25-inch adapter, ensuring compatibility with a wide range of eyepieces and accessories. The primary eyepiece included is a 28 mm wide-field 2-inch model, providing a solid starting point for its intended use. The mount itself, the CGEM II, is rated for a 40 lbs load capacity, which is more than sufficient for the optical tube and common accessories.

Performance & Functionality

The primary job of the Celestron CGEM II 700 Maksutov-Cassegrain Telescope is to provide exceptional views of planets, the Moon, and other small, high-contrast celestial objects, and it excels at this. The f/15 focal ratio is its greatest asset, allowing for extreme magnifications that reveal stunning detail. I was consistently impressed by the sharpness and clarity of lunar features like craters and rilles, and the subtle bands of Jupiter were always visible.

However, this extreme focal length also means that any atmospheric turbulence is amplified. On nights with poor seeing conditions, pushing the magnification too high can result in blurry, frustrating views, but this is an inherent characteristic of high-power planetary scopes. The drive system with its low cog DC Servo motors and steel worm gears allows for precise tracking, keeping celestial objects centered for extended viewing or imaging sessions. The Celestron CGEM II 700 Maksutov-Cassegrain Telescope performs its core function exceptionally well, though users must be mindful of atmospheric conditions.

Design & Ergonomics

The design of this Celestron optic is clearly driven by function. The beige optical tube is substantial and well-constructed, with a focus on minimizing internal reflections. The robust CGEM II equatorial mount and tripod provide a stable platform, crucial for high-magnification observing. While the mount and tripod are designed to disassemble into manageable pieces for transport, it’s still a significant system to move.

The ergonomics are generally good for its intended purpose. The focus knob is smooth and precise, allowing for fine adjustments needed at high power. The included 2-inch visual back and the accessory port for the finderscope are well-placed and secure. The tactile feel of the mount’s controls is solid, though the slow-motion controls can be a bit stiff initially. Overall, it’s a well-built instrument that feels like it can withstand regular use in the field.

Durability & Maintenance

Given its substantial build and focus on robust components like steel worm gears, the Celestron CGEM II 700 Maksutov-Cassegrain Telescope appears built to last. The optical coatings are durable, provided basic care is taken. The equatorial mount, with its sealed bearings, should also offer long-term reliability.

Maintenance is straightforward, focusing on keeping the optics clean and the mount’s moving parts free from debris. There are no obvious weak points that jump out; the design prioritizes longevity. The tool-free disassembly of the mount and tube is a thoughtful touch that aids in storage and transport, reducing the risk of accidental damage.

Accessories and Customization Options

The included accessories are thoughtfully chosen to complement the telescope’s capabilities. The 2-inch Visual Back and the 2-inch Star Diagonal with 1.25-inch adapter are essential for utilizing a range of eyepieces. The 28 mm wide-field 2-inch eyepiece offers a good starting point for its intended use, providing a decent balance of field of view and magnification. The 8×50 straight-through finderscope is a premium addition that significantly enhances the ease of use.

The optical tube’s compatibility with 2-inch accessories is a major plus, allowing for expansion with larger Barlow lenses and a wider selection of premium eyepieces for detailed planetary or deep-sky work. The CGEM II mount also supports the Celestron StarSense AutoAlign accessory, which can greatly simplify the alignment process for those seeking automation.

Pros and Cons of Celestron CGEM II 700 Maksutov-Cassegrain Telescope

Who Should Buy Celestron CGEM II 700 Maksutov-Cassegrain Telescope?

This telescope is ideally suited for serious visual observers and planetary imagers who prioritize detailed views of the Moon, planets, and bright deep-sky objects. Amateur astronomers with a dedicated observing location or those willing to transport a larger, high-quality instrument will find it immensely rewarding. It’s also a great choice for observers in urban environments where its contrast-enhancing capabilities shine.

Those who are looking for a wide-field scope for viewing large nebulae or galaxies should consider alternative designs. Beginners who are new to astronomy might find the setup and operation of an equatorial mount and the high magnification optics a bit daunting initially, though it’s a fantastic learning tool. A good quality dew shield and potentially a more advanced autoguider system for imaging would be excellent complementary accessories.

Conclusion on Celestron CGEM II 700 Maksutov-Cassegrain Telescope

The Celestron CGEM II 700 Maksutov-Cassegrain Telescope is a specialized instrument that delivers on its promise of exceptional high-power views. Its Maksutov-Cassegrain design, combined with the robust CGEM II mount, provides a powerful and stable platform for exploring the solar system and brighter deep-sky targets. The optical quality, enhanced by StarBright XLT coatings, is truly superb, offering a level of detail that will thrill any enthusiast.

While its extreme focal length means it’s not an all-rounder for every type of astronomical object, its performance in its intended niche is outstanding. The price point reflects the quality of the optics and the sophisticated equatorial mount, making it a significant investment. For the dedicated planetary and lunar observer seeking the pinnacle of detail within this aperture class, the Celestron CGEM II 700 Maksutov-Cassegrain Telescope is an easy recommendation. It’s a serious instrument for serious stargazers.