Celestron CGEM II - 925

CGEM II 925 HD combines Celestron's newly redesigned CGEM II computerized equatorial mount with its acclaimed EdgeHD optical system. With over 9 inches of aperture and our premium StarBright XLT coatings, the CGEM II 925 HD gives you over 1000 times the light gathering power than the unaided eye.

Designed to give diffraction limited performance and offer more resolution than the 800 with less weight than the 1100, the CGEM II 925 HD is a premier astroimaging telescope.

Optical Tube Info:

See the Universe in HD:
EdgeHD is an aplanatic, flat field Schmidt-Cassegrain telescope that produces aberration-free images across a wide visual and photographic field of view. The optical system was designed to reduce more than just off-axis star coma; it also provides an astrograph-quality flat focal plane all the way to the edge of the field of view.

True Astrograph Quality:
Many optical designs that advertise themselves as "astrographs" actually only produce pinpoint stars across a curved focal plane. While this may be acceptable for some visual observing, stars will appear out of focus at the edge when used with the flat chip sensor of a digital camera. EdgeHD optics produce a focal plane more than three-times flatter than a standard Schmidt-Cassegrain telescope and dramatically flatter than competing coma-free designs. This guarantees you visibly sharp stars across some of the largest CCD chips available today. Learn more about EdgeHD technology.

Improved Performance:
Superior edge performance not only creates rounder, more pleasing stars, but actually improves the resolution and limiting magnitude when compared to telescopes of equal aperture. With Celestron’s StarBright XLT optical coatings on every surface, EdgeHD optics gives you maximum light throughput across the widest visual and photographic spectrum.

Mechanical Features:
In addition to EdgeHD’s optimized optical design, the telescope tube has been redesigned to make sure you get the most from your optics each and every night.

Mirror clutches - Flexible tension clutches hold the mirror in place and reduce image shift when taking long exposure astro-images. Once focused, the flexible rods allow the mirror to be held in place without putting any force or pressure on the mirror assembly, keeping the image centered in the eyepiece (or on the sensor).
Tube vents - Cooling vents located on the rear cell allow hot air to be released from behind the primary mirror. Each vent has an integrated 50-mesh filter guaranteed to let warm air out without letting dust in.
Fastar versatility - EdgeHD is the most versatile imaging telescope available today. At its native f/10, you can achieve the image scale necessary to capture the smallest of deep sky objects. A Barlow gives you added power for high-resolution planetary, lunar and solar imaging. All EdgeHD optical tubes are Fastar-compatible, allowing the secondary mirror to be removed and replaced with a third party lens accessory for ultra-fast f/2 wide field imaging.
Individually Tested
Every EdgeHD that ships has been tested not only for the surface quality of each optical component, but also with a camera and artificial star to ensure the imaging system meets our rigid quality assurance. This “final acceptance test” confirms the EdgeHD will perform in the field and deliver high-quality astroimages.

Spec:

• Optical design: EdgeHD
  
• Optical coating: Starbright XLT (Fully multi-coated)
  
• Telescope aperture: 234.95mm (9.25")
  
• Focuser size (inches): 2" SC thread, 1.25"
  
• Tube (material): Aluminum
  
• Tube weight: 9.53kg
  
• Tube length: 22in (559 mm)
  
• Aperture ratio: f/10
  
• Resolution (DAWES): 0.49 arcseconds
  
• Resolution (RAYLEIGH): 0.59 arcseconds
  
• Focal length: 2350mm (93 in)
  
• Secondary mirror obstruction: 8.5cm
  
• Secondary mirror obstruction relative to diameter: 36.20%
  
• Secondary mirror obstruction relative to surface: 13.00%
  
• Visual field: 0.55°
  
• Limit size: 14.4
  
• Highest useful magnification: x555
  
• Light gathering capacity (compared to the human eye): x1127
  

Mount Spec:

• Instrument load capacity: 18 kg
  
• Alignment Methods: AutoAlign, 2-Star Align, Quick Align, 1-Star Align, Last
• Alignment, Solar System Align
  
• Database: Over 40,000+ properties, 100 custom listings, More information on over 200 properties
  
• Counterweights: 1 x 7.7kg
  
• Mount: Equatorial mount (motorized)
  
• Mount weight (EQ): 18.1kg
  
• Mount control: Computer controlled (GOTO)
  
• Tracking speeds: Sidereal, solar and lunar
  
• Tracking modes: EQ North and EQ South
  
• Pole height adjustment: 15º – 70º
  
• Dovetail compatible: 3" CGE rail
  
• Panning speed: 9 speeds, maximum 5°/sConnections: 1x hand controller, 1x AUX, 1x autoguider port, 1 USB 2.0 (on the hand controller)
  
• Hand controller: NexStar+ hand controller, two-line LCD display with 16 characters, 19 backlit keys, USB 2.0 port for PC connection
  
• Motor drive: DC servo motors with extremely low starting resistance, avoids voltage peaks
  
• Power requirements: 12VDC, 3.2A

Whats included:

1. Focal length eyepiece: 23mm
   
2. Incl. accessories: 9.25" EdgeHD telescope with 3" rail (Losmandy style) 9x50 finder, 2" star diagonal, 1.25" adapter, 23mm Luminos wide angle eyepiece, CGEM-II mount, 2 counterweights, tripod, NexStar hand controller
   
3. Viewfinder: 9x50
   
4. Zenith prism: 2" with 1.25" adapter