Designed with the discerning amateur astrophotographer in mind, the Celestron CGEM II 700 180mm f/15 Maksutov-Cassegrain Telescope is a powerful astronomical tool that remains manageable and portable. Combining a large-aperture catadioptric optical tube assembly (OTA) with a strong and stable CGEM II mount produces an observational and imaging rig that can reveal stunning details of the moon and planets with the ability to resolve wispy nebula, fuzzy galaxies, and tight binary stars.

The Maksutov design exchanges the conventional front corrector plate of a Schmidt with a convex meniscus lens, resulting in a smaller secondary mirror that limits obstruction and increases contrast, while eliminating the need for periodic collimation. This modified optical path results in a slower focal ratio and narrower field of view versus a similar Schmidt, but the optical benefits, when coupled with the larger aperture and StarBright XLT optical coatings, make it more than capable for long-exposure photography techniques.

The CGEM II GoTo equatorial mount is engineered to carry a 40-pound payload, and with the OTA weighing under 20 pounds there is plenty of payload capacity for all your observation or imaging gear. High-torque dual DC servo motors enable it to smoothly and accurately slew and track all night long. To provide a stable platform for the mount and OTA, a heavy-duty stainless steel tripod is included that sports large 2" legs and an accessory tray that doubles as a stabilizer.

The brain of the whole system is the NexStar+ computer controller. Equipped with a database of 40,000 objects, including the planets, stars, nebulae, galaxies, and the complete Messier catalog, it can also be programmed with up 100 custom user-defined objects with filters added for custom object lists. Its intuitive menu-driven user interface provides the power to observe the heavens with nine slew speeds and three tracking rates, plus anti-backlash compensation and Permanent Periodic Error Correction (PPEC) for smoother movements in the motors and improved tracking over time. Features such as guided tours, extended information on 200 popular objects, and multiple alignment options make the NexStar+ controller easy to use and invaluable to new users and experienced stargazers.

This OTA's compact form factor belies its observation power and resolution and is ideally suited as a grab-and-go option for quick observation sessions or heading out to remote locations.

180mm Aperture Maksutov-Cassegrain OTA    2700mm Focal Length, f/15 Focal Ratio    StarBright XLT Multi-Coated Optics    28mm Eyepiece, 90° Star Diagonal    2" Visual Back, 1.25" Reducer Adapter    CGEM II Motorized GoTo EQ Mount    NexStar+ Computer Hand Controller    40,000-Object Database    Guided Tours and Custom Object Filters    2" Stainless Steel Tripod

• 180mm (7") diameter aperture enables near- and deep-sky viewing without being prohibitively large or heavy for easy transport to viewing locations
• Long 2700mm focal length provides a high magnification potential
• Front convex meniscus lens corrects spherical and chromatic aberrations as well as comas (off-axis aberrations) across the entire field of view
• Smaller secondary mirror versus Schmidt-Cassegrains reduces obstructions and increases contrast
• Proprietary StarBright XLT fully multi-coated optical system
• Resolution: 0.64 arcsec (Rayleigh), 0.52 arcsec (Dawes)
• Secondary mirror obstruction: 40mm (1.57"), 22% by diameter, 5% by area
• Internal primary mirror focusing mechanism
• 2" visual back accepts larger eyepieces and accessories

StarBright XLT Coating System:

• Multi-layer mirror coatings made from layers of aluminum, SiO2 (silicon dioxide), and TiO2 (titanium dioxide)
• Reflectivity is flat across the light spectrum, for both astrophotography/astro-imaging
• Multi-layer anti-reflective coatings made from layers of MgF2 (magnesium fluoride) and HfO2 (hafnium dioxide)
• High-transmission Water White glass corrector lens with 97.4% light transmission

Features:

• Intuitive menu-driven user interface
• Nine Slew Speeds: 2x, 4x, 8x, 16x, 32x, 0.3°/sec, 1.0°/sec, 2°/sec, 4°/sec
• Multiple Tracking Rates: Sidereal, Lunar, and Solar
• Anti-Backlash Correction: Trains out intrinsic play in gears for smoother movement and tracking
• Permanent Periodic Error Correction (PPEC): Improves tracking precision for long-exposure astrophotography and imaging

• 40,000-object database
• 100 user-defined objects for customization
• Filters for creating custom object lists
• Solar system: All seven planets plus the moon, sun, and Pluto
• Custom lists of all the brightest stars, double stars, variable stars, and asterisms
• Custom lists of all the best galaxies, nebulae, and clusters as well as the complete Messier catalog and select NGC objects

• All-Star Polar Alignment system enables the user to choose any bright star in the sky, not just the North (Pole) Star, and the system will calculate and assist in accurate polar alignment for better tracking during long-exposure astrophotography
• Alignment options: One- or Two-star, Solar system, Quick, and Last
• Sky Tour: Based on location, date, and time, the system shows the best objects in the sky and automatically slews to them
• Object Info: Provides useful information about the selected object such as magnitude and constellation; includes extended information about 200 popular objects

• 2-line, 16-character LCD window with red backlighting for comfortable viewing without affecting night-adjusted vision
• 19 function keys, backlit in red
• Micro-USB port: Connect to a computer, for use with software programs for point-and-click slewing capability and updating firmware via PC

Mount:

• German equatorial mount
• 40-pound payload capacity
• 15-70° latitude adjustment range
• Dual-axis low-cog DC servo motors with optical encoders for smooth tracking and quiet operation
• High-torque motors provide smooth tracking and slewing for heavy OTAs
• Autoguider port for making corrections while astroimaging
• Dual Vixen/Losmandy dovetail saddle, compatible with CG-5 and CGE bars
• Long clutch levers make tightening and loosening of clutches easier for manual movement
• Internal cables/wires for snag-free operation
• Runs on included 12 VDC, 3.2A car/vehicle power supply

• Stainless steel legs
• Heavy-duty 2" diameter
• Graduated markings on lower section for height repeatability
• Accessory/eyepiece holder tray that doubles as leg spreader/lock
• Weight: 20 pounds

Eyepiece:

• Large 2" nosepiece provides a wide field of view for comfortable viewing
• 28mm focal length delivers a low 96x magnification
• Threaded to accept most 2" eyepiece filters

• 2" nosepiece accepts larger eyepieces, 2" snout allows it to fit into larger focusers without needed adapters
• 90° angle places the user's head in a comfortable viewing position, especially when the OTA is aimed directly overhead
• Star configuration corrects view horizontally, but view remains reversed

• Inserts into the visual back or diagonal to allow the use of the more common 1.25" eyepieces and accessories
• Simple drop-in design for fast changes from 2" to 1.25" gear

• Low 8x magnification preserves wide field of view to more easily find alignment or guide stars
• Large 50mm aperture helps to see dimmer objects and stars for more alignment options and finding guide stars for autoguiding during long-exposure astrophotography
• Includes mounting bracket

Related Questions and Answers

Q: 1. Is the dc jack that is on the telescope is of non-standard length ? I couldn't fit any of the existing 12v dc power adapters that I had. Do telescopes have a different jack length ? Is there a way I can use the standard 12v dc power supply with it (using some connectors perhaps ?) . Standard dc jack length is 10mm, while this telescope requires around 13mm. Is that correct ?

A: The Celestron AC to DC Power Adapter (BH #CEACDCPA • MFR #18778) is the correct power adapter for the Celestron Astro Fi 102mm f/13 Maksutov-Cassegrain Telescope. This is a 12 volt 2A with a 5.5mm DC plug on the end. This plug has an inner diameter of 2.1mm (.08"), and a length of 10mm - 15mm (.39" - .59").

Q: 2. What exactly can you see in detail with a telescope like this? Do you just see the moon in more detail, or can you actually see a bit more of the solar system? Sorry, unexperienced person here.

A: So it really all depends on where you live, and the light pollution. If you are in an area where there there is a lot of Light Pollution then you really won't see much. The Scope is an excellent Scope. If you are in an area with little to no light pollution, then yes this would be an excellent choice.

Q: 3. a) Can we use a power adapter (dc/AC/Car) with this if battery runs out ? If yes, which model ?

A: Yes, there are a couple power options for this. One can use the Celestron AC to DC Power Adapter, BH #CEACDCPA (https://bhpho.to/3yhjx6R). One can also use the Celestron Car Battery Adapter (25'/7.7 m), BH #CECBAU2000 (https://bhpho.to/3vNHf98).

Q: 4. Can a t adapter be used with this to take pictures with camera?

A: Yes you can,

Q: 5. Do you sell a focal reducer that would be suitable for this telescope, the 7 inch Maksutov f/15, or do you know of one?

A: The Celestron f/6.3 Reducer/Corrector will be compatible with this scope. Website link: http://bhpho.to/1JT4a4N

Q: 6. what is the actual size of the central obstruction INCLUDING the baffle?

A: The Length is 22 , and the Width is 8.625 .

Q: 7. Can you use a hand controller thru the aux connectors and not just smart phone or tablet just in case say a person's phone or tablet breaks?

A: Yes, you can use a NexStar hand controller through the aux port to control the telescope. Sincerely, Garrett at Celestron

Q: 8. Where I view stars there is no internet or cellular service. Can this telescope still track without an internet connection?

A: It utilizes an integrated antenna to emit a local Wi-Fi signal so you can control the mount via direct wireless connection with Android and iOS smartphones and tablets running the free SkyPortal app. Tracking Rates: Sidereal, solar, and lunar; automatic tracking for near- and deep-sky objects

Q: 9. Does this come with a case?

A: A case is not included.

Q: 10. How we can connect one photo machine to the Celestron Astro Fi 102mm f/13 Maksutov-Cassegrain Telescope ?

A: If you are referring to Photography cameras we have a number of different T-Mount adapter for a variety of cameras. https://bhpho.to/2njCYde