Celestron CGEM II 700 Maksutov Cassegrain Telescope
- Celestron 700 Maksutov-Cassegrain telescope with f/15 focal ratio provides high contrast views of the planets and lunar landscapes
- Perfect for serious planetary imagers and visual observers
- Celestron’s premium StarBright XLT coatings ensure maximum light transmission
- The CGEM II with its 40 lb load capacity is Celestron’s updated CGEM equatorial mount with newer features
- The drive system utilizes low cog DC Servo motors with integrated optical encoders
- Features steel worm gears supported by precision sealed bearings, and brass worm wheels for smooth, accurate slewing and tracking performance with little backlash
- Accessories included: 2” Visual Back, 2” Star Diagonal with 1.25” adapter, 28 mm eyepiece (2”), and an 8x50 finderscope
This Celestron 700 Maksutov-Cassegrain CGEM II telescope (CGEM II 700 Mak) is a specialized instrument designed for detailed, high contrast views of smaller celestial objects like the planets. This Maksutov-Cassegrain optical tube and sturdy equatorial mount and tripod will provide unparalleled views of the planets and up-close views of the lunar surface, including craters and maria. Maksutov scopes are also well suited to hunting smaller, fainter, deep sky objects such as globular clusters and planetary nebulae. Astronomers located in urban areas will appreciate the 700 Maksutov-Cassegrain CGEM II telescope's ability to bring out more contrast in celestial objects. Transporting the entire system to a dark site is simple. The optical tube, mount head, tripod, counterweight bar, and counterweight all disassemble, with no tools required, into separate manageable pieces.
The Maksutov is a catadioptric telescope, which means the optical design includes both a lens and a mirror. The light coming through this kind of scope passes through the corrector lens to the primary mirror and back to a spherical secondary mirror, then back down through a perforation in the primary mirror before it hits your eyepiece. Images are bright, sharp, and virtually free of chromatic aberration. This Maksutov-Cassegrain’s optical design (also known as a spot-Maksutov) offers several unique benefits. Instead of a secondary mirror, the Mak features a “secondary spot” of reflective coating applied directly to the inside of the corrector plate. Because of this, the telescope does not require frequent collimation like a Schmidt-Cassegrain. Also, the secondary spot is significantly smaller than a traditional Schmidt-Cassegrain secondary mirror, giving the Mak its signature high-contrast views.
The Celestron CGEM II is a sturdy equatorial mount capable of rigidly supporting the 700 Mak. Its 40 lb load capacity can handle the 19 lbs optical tube with ease, leaving lots of capacity to spare for your camera and any accessories. The heavy-duty adjustable height tripod has 2” diameter steel tripod legs with graduated markings that make it easy to extend the legs to the same height. The 700 Mak connects directly to the CGEM II with its CGE dovetail mounting bar. Expect a vibration-free setup, even in somewhat windy conditions. The 700 Mak connects using its CGE dovetail mounting bar.
The heavy-duty adjustable height tripod has 2” diameter steel legs with an extra-wide stance for improved stability. Graduated markings on the tripod legs make it easy to extend them to the same height and level the tripod.
This Celestron CGEM II mount is packed with functionality and conveniences that make imaging with the 700 Mak easy. The mount can be easily aligned to the Celestial Pole. The fully computerized mount will automatically “GoTo” any of the 40,000+ astronomical objects selected from the NexStar+ hand controller’s database and then track the object as it appears to move as the Earth rotates.
Designed with imaging in mind, the CGEM II motor drive system guarantees accurate tracking of objects. At the heart of the system are low cog DC servo motors with integrated optical encoders. The low cog design helps the motors run smoothly, while the integrated optical encoders provide accuracy. The motors connect to the worm gears. The steel worm gears are supported by precision bearings and drive a brass worm wheel, which also helps ensure a smooth drive system. Expect minimal backlash and no binding.
To track objects in the night sky, the mount must first be polar-aligned. Celestron makes this process easier than ever with the innovative All-Star Polar Alignment procedure. No extra equipment, such as a polar finder scope, is required. (But an optional polar alignment finder scope is available if desired.) The accurate alignment can usually be completed in about 15 minutes, even without a clear view of Polaris.
To mitigate periodic tracking errors, the CGEM II has Permanent Periodic Error Correction (PPEC). This allows you to run a routine to record the periodic errors only once; the recording is kept in memory, and subsequently corrects for the mount’s periodic tracking error. If an even higher level of tracking accuracy is desired, the CGEM II also has a dedicated autoguider port to connect an autoguiding camera directly to the mount.
For remote imaging, the mount needs a way to be controlled by an external computer. The CGEM II connects to a computer via USB 2.0 via the included hand controller. It provides 2 auxiliary ports for optional accessories. The included NexStar+ hand controller with its USB 2.0 port for computer connection can be used with optional third-party telescope control software by use of an ASCOM driver.
What's In The Box? The Celestron CGEM II 700 Maksutov Cassegrain Telescope comes complete with a 2” Visual Back, a 2” Star Diagonal with 1.25” adapter, a 28 mm wide-field 2” eyepiece, and a large 8x50 straight-through finderscope. The optical tube accommodates the larger 2” accessories.
Optical Tube Specifications:
|Aperture||180 mm (7.08")|
|Focal Length||2700 mm (106.3")|
|Focal Length of Eyepiece||28 mm (1.1") 2"|
|Magnification of Eyepiece||96x|
|Finderscope||8x50 Straight Through|
|Star Diagonal||2" with 1.25" adapter|
|Highest Useful Magnification||420x|
|Lowest Useful Magnification||67x|
|Limiting Stellar Magnitude||13.9|
|Resolution (Rayleigh)||0.64 arcsecond|
|Resolution (Dawes)||0.52 arcsecond|
|Light Gathering Power (Compared to human eye)||661x|
|Secondary Mirror Obstruction||40 mm (1.57")|
|Secondary Mirror Obstruction by Diameter||22%|
|Secondary Mirror Obstruction by Area||5%|
|Optical Coatings||StarBright XLT|
|Optical Tube Length||571.5 mm (22.5")|
|Optical Tube Diameter||222.25 mm (8.75")|
|Optical Tube Weight||19 lb (8.6 kg)|
|Dovetail||CGE Dovetail Bar|
|Mount Type||Computerized Equatorial|
|Instrument load capacity||40 lb (18 kg)|
|Height adjustment range (includes mount and tripod)||1346 mm - 1651 mm (53" - 65")|
|Tripod Leg Diameter||50.8 mm (2") Steel tripod with graduated markings on lower section|
|Latitude adjustment range||15° - 70°|
|Mount Head Weight||40 lb (18.14 kg)|
|Tripod Weight||20 lb (9 kg)|
|Weight of Counterweights||1 each x 17 lb|
|Slew Speeds||9 slew speeds - max speed 4.5°/second|
|Tracking Rates||Sidereal, Solar and Lunar|
|Tracking Modes||EQ North & EQ South|
|Dovetail Compatibility||Dual saddle plates (Vixen and CGE saddle)|
|Number of Auxiliary ports||2 Aux ports (Hand Control uses one Aux port)|
|USB Port||Yes, input for Mount and Hand Control|
|Power Requirements||12V DC, 3.2 amps|
|Motor Drive||DC servo motors|
|Alignment Procedures||2-Star Align, 1-Star Align, Solar System Align, Last Alignment, Quick Align|
|Periodic Error Correction||Yes|
|Computerized Hand Control||2 line x 18 character backlit Liquid Crystal Display, 19 LED backlit buttons, USB 2.0 port for PC connection|
|NexStar+ Database||40,000+ objects, 100 user defined programmable objects. Enhanced information on over 200 objects|
|Software||Celestron's Starry Night Special Edition Software, SkyPortal App|
|Total Kit Weight||90.5 lb (41 kg)|
|Included Items||700 Maksutov Cassegrain OTA | CGEM II Equatorial Head | CGEM II Tripod | Accessory Tray | 1 x 17 lb counterweight | NexStar+ Hand Control | 8mm Allen Wrench | 12V DC Power Cable|