The CGEM II 700 Mak telescope (CGEM II 700 Mak) is a specialized instrument designed for providing detailed, high-contrast views of smaller celestial objects, particularly planets. This telescope, featuring a Maksutov-Cassegrain optical tube and a sturdy equatorial mount with a tripod, offers exceptional planetary observations and close-up lunar views, revealing craters and maria in great detail. Maksutov-Cassegrain telescopes like this one are also well-suited for spotting smaller, fainter deep sky objects such as globular clusters and planetary nebulae. Additionally, astronomers in urban areas will appreciate the Mak's ability to enhance contrast in celestial objects.

Transporting the entire system to a dark observing site is made easy as well. The optical tube, mount head, tripod, counterweight bar, and counterweight can all be disassembled into separate, manageable pieces without the need for tools.

Maksutov-Cassegrain Optical Design:

The Mak is a catadioptric telescope, incorporating both a lens and a mirror in its optical design. Light entering the Mak passes through a corrector lens to the primary mirror, then reflects off a spherical secondary mirror before reaching the eyepiece. This optical arrangement results in bright, sharp, and nearly chromatic aberration-free images.

The Maksutov-Cassegrain design offers several advantages. Unlike Schmidt-Cassegrain telescopes, the Mak uses a "secondary spot" of reflective coating directly applied to the inside of the corrector plate, eliminating the need for frequent collimation. Moreover, the secondary spot is notably smaller than the secondary mirror found in traditional Schmidt-Cassegrain telescopes, contributing to the Mak's characteristic high-contrast views.

It's important to note that Maksutov-Cassegrain telescopes, due to their larger and heavier corrector plates, require more time to cool down and adapt to ambient air temperature compared to same-aperture Schmidt-Cassegrain telescopes.

CGEM II Mount & Tripod:

The CGEM II is a robust equatorial mount capable of securely supporting the 700 Mak telescope. With a load capacity of 40 lbs, it effortlessly handles the 19 lbs optical tube, leaving ample capacity for additional accessories and a camera. The tripod, featuring adjustable height and sturdy 2" diameter steel legs with graduated markings, makes it easy to extend the legs to the same height. The 700 Mak directly attaches to the CGEM II using its CGE dovetail mounting bar.

The mount is equipped with various functionalities that simplify imaging with the 700 Mak. The fully computerized mount performs automatic "GoTo" slews to over 40,000 astronomical objects from the NexStar+ hand controller's extensive database, tracking them as they move across the night sky.

Designed with imaging in mind, the CGEM II's motor drive system ensures accurate tracking during exposures. It employs low cog DC servo motors with integrated optical encoders, delivering smooth motor operation with high precision. Steel worm gears turn against brass worm wheels, further enhancing the motor drive system's smooth and accurate operation.

To track celestial objects, polar alignment is essential. Celestron simplifies this process with the innovative All-Star Polar Alignment procedure, which eliminates the need for additional equipment like a polar finder scope (though an optional one is available). Typically, alignment can be completed in about 15 minutes, even without a clear view of Polaris.

All mounts exhibit some level of "periodic tracking error" caused by minor gear imperfections. To address this, the CGEM II features Permanent Periodic Error Correction (PPEC), allowing users to record periodic errors once, which are then stored in memory and used to correct for any tracking errors during use. For even greater tracking accuracy, the CGEM II offers a dedicated autoguider port to connect an autoguiding camera directly to the mount, correcting any remaining tracking errors.

When imaging, cable management can be challenging due to multiple cables from the camera, power source, computer connection, and autoguider. To minimize cable-related issues and prevent unwanted snags, all mount cabling is internal, eliminating the need to connect or disconnect an external Dec. motor cable when setting up or breaking down the mount.

Accessories Included:

The CGEM II 700 Mak telescope package comes complete with a 2" Visual Back, a 2" Star Diagonal with a 1.25" adapter, a 28 mm wide-field 2" eyepiece, and a large 8x50 straight-through finderscope. The optical tube accommodates larger 2" accessories such as 2" Barlow lenses, a 2" eyepiece and filter kit, and wider field-of-view eyepieces.

StarBright XLT Technology:

Celestron's StarBright XLT optical coating system is a revolutionary advancement, outperforming other coatings in the commercial telescope market. It comprises three major components:

1. Enhanced multi-layer mirror coatings composed of precise layers of aluminum, SiO2 (quartz), TiO2 (titanium dioxide), and SiO2 (silicon dioxide). These coatings ensure high reflectivity across the spectrum, benefiting both imaging and visual observation.

2. Multi-layer anti-reflective coatings consisting of precise layers of MgF2 (magnesium fluoride) and HfO2 (hafnium dioxide). The use of hafnium in these coatings, despite its high cost, results in a wider bandpass compared to the titanium-based coatings found in competitors' telescopes.

3. High-transmission water white glass for the corrector lens instead of soda lime glass. Water white glass transmits about 90.5% of light without anti-reflective coatings, an improvement of 3.5% compared to uncoated soda lime glass. When combined with StarBright XLT's anti-reflective coatings, the average transmission reaches 97.4%, an 8% enhancement.

These components collectively make StarBright XLT one of the most advanced optical coatings available.

Celestron's Starry Night Special Edition Software:

Starry Night is a planetarium software package offering easy-to-understand explanations and stunning visual representations of various night sky phenomena. It provides information on extrasolar planets imagery, 3D star rendering, observation planning, telescope control, multi-panel printing, and more. Starry Night is compatible with macOS and Microsoft Windows.

Specifications

Software and Documentation