Celestron CGX 1100 RASA Equatorial Telescope

RASA 11" Optics: An f/2.2 Astrograph with a 43.3mm Image Circle

The core of this system is the 11" Rowe-Ackermann Schmidt Astrograph, an optical design engineered for one purpose: capturing deep-sky images in a fraction of the time of a conventional f/10 telescope. The native f/2.2 focal ratio dramatically reduces exposure time, which lessens tracking demands on the equatorial mount and often eliminates the need for autoguiding. This speed makes capturing faint details in nebulae and galaxies more accessible than ever before.

The 4-element rare-earth glass optics and StarBright XLT coatings are corrected for a 43.3mm image circle, fully illuminating full-frame sensors and providing a usable field up to 52mm in diameter. This wide, flat field is free of coma and field curvature, producing spot sizes under 4.4 µm RMS and ensuring sharp stars from the center to the edge of the frame. The optical design maintains 83% illumination even 21mm off-axis, preventing significant vignetting on large camera sensors.

Advanced OTA Features: The Ultra-Stable Focus System and 12V Cooling Fan

The RASA 11" incorporates Celestron's Ultra-Stable Focus System (USFS), which uses a precision linear ball bearing to support the primary mirror. This system is engineered to minimize both focus shift and mirror flop, two common issues in moving-mirror designs that can ruin long exposures. The result is a stable, repeatable focus mechanism that holds position as the telescope slews across the sky. For added convenience, the focuser is compatible with the optional Celestron Focus Motor.

• Integrated Cooling: A built-in 12V DC MagLev fan reduces the telescope's cooldown time, helping the optics reach thermal equilibrium with the ambient air more quickly for sharper images.
• Included Adapters: The astrograph comes ready for imaging with both 42mm T-thread and 48mm camera adapters, providing a standard 55mm back focus distance.

CGX Mount: 55 lb Capacity and All-Star Polar Alignment

The Celestron CGX mount is designed to carry the 43 lb RASA 11" optical tube with capacity to spare for a heavy camera, filter wheel, and guidescope. Its 55 lb instrument capacity is driven by high-torque DC servo motors, delivering responsive slewing up to 4° per second and precise tracking for astrophotography. The mount's intelligence lies in its NexStar+ hand control and CPWI software suite.

Celestron's All-Star Polar Alignment allows you to achieve an accurate polar alignment using any bright star, even if Polaris is obstructed. For permanent setups, the mount features Permanently Programmable Periodic Error Correction (PPEC) to train out the worm gear's periodic error, enabling longer, unguided exposures. The NexStar+ database contains over 40,000 objects, putting the entire night sky at your fingertips.

CGX Ergonomics: A Stable Platform with Integrated Cable Management

The CGX was engineered for stability and ease of use in the field. The low-profile equatorial head lowers the center of gravity, increasing stability on the heavy-duty 2" steel tripod. The mount features built-in home and limit sensors, allowing it to always know its orientation and avoid cable wrap or collisions with the tripod. Cabling for accessories can be run through the mount itself, preventing snags during operation.

• Dual Saddle Plate: The CGX is equipped with a dual-fit saddle that accepts both CGE and CG-5 style dovetail bars, offering flexibility for mounting different optical tubes.
• User-Friendly Adjustments: Large, ergonomic knobs for altitude and azimuth adjustments make polar alignment easier, even with gloves on. The mount supports a wide latitude range from 3° to 65°.