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Celestron CGEM II 800 8" f/2 Rowe-Ackerman Schmidt Astrograph GoTo Telescope

SKU: CNRASA8CGEM MFR: 12020
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Key Features

  • Capture stunning astrophotos with the 8" Rowe-Ackermann Schmidt Astrograph telescope.
  • Enjoy superior optical quality with StarBright XLT coatings for brighter, clearer views.
  • The integrated cooling fan in this telescope reduces thermal currents for optimal imaging.
  • Achieve pinpoint stars to the edge of the field with a large 22 mm image circle.
  • Experience stable, precise tracking with the robust CGEM II GoTo telescope mount.
  • Easily attach your camera with included T-thread and C-thread camera adapters.
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Celestron CGEM II 800 8" f/2 Rowe-Ackerman Schmidt Astrograph GoTo Telescope Specifications

  • Optical Design

    Rowe-Ackermann Schmidt

  • Aperture

    203 mm (8")

  • Focal Length

    400 mm (15.74")

  • Focal Ration

    F2.0

  • Central obstruction diameter

    93 mm (3.66") (46% of aperture diameter)

  • Light Gathering Power

    843x

  • Optical Coatings

    StarBright XLT

  • Optical Coatings

    StarBright XLT

  • Resolution (Rayleigh)

    0.68 arc seconds

  • Resolution (Dawes)

    0.57 arc seconds

  • Image Circle

    22 mm (.86") ½, 3.15 degree

  • Useable field

    32 mm (1.26") ½, 4.6½, only minimal performance loss at edge of FOV

  • Wavelength range

    390 - 800 nm

  • Spot size

    < 4.6 ½m RMS across image circle

  • Off-axis Illumination

    93% at 11 mm (.43") off-axis

  • Optical Window

    46 mm (1.81") ½

  • Back focus with included camera adapter

    25 mm (.98")

  • Back focus from top of threaded collar

    29 mm (1.14")

  • Optical Tube

    Aluminum

  • Focuser

    Ultra-Stable Focusing System

  • Finderscope

    Not included

  • Other Features

    Air-cooling system, integrated filter mount

  • Optical Tube Weight

    17 lbs (7.7 kg)

  • Dovetail

    CGE Dovetail Bar

  • UPC Code

    050234120203

4 Accessories for Celestron CGEM II 800 8" f/2 Rowe-Ackerman Schmidt Astrograph GoTo Telescope

  • All Accessories (4)
  • Adapters & Mounts (2)
  • Filters (1)
  • Mount Accessories (1)

About Celestron CGEM II 800 8" f/2 Rowe-Ackerman Schmidt Astrograph GoTo Telescope

Experience the power and precision of Celestron's CGEM II 800 8" f/2 Rowe-Ackermann Schmidt Astrograph (RASA) GoTo Telescope, a portable astrograph designed to capture breathtaking wide-field deep sky images in mere seconds. This innovative f/2.0 system is ideally suited for use with today's color astronomical CMOS cameras, compact CCD cameras, and mirrorless cameras.

The 8" RASA's fast focal ratio and patented optical design allow you to produce sharp, detailed images, often eliminating the need for an autoguider. Weighing just 17 pounds, this telescope is easily transportable, making it perfect for trips to remote dark sky locations.

The 8" RASA is a dedicated imaging telescope, delivering a flat field devoid of optical aberrations for razor-sharp stars across a broad field of view. It enables you to capture stunning deep-sky astronomical images without the typical challenges presented by longer focal length instruments, and at a fraction of the cost.

This telescope is the latest addition to the acclaimed RASA family, offering a more portable and affordable alternative to the highly praised RASA 11. Like its predecessor, the 8" RASA boasts a range of carefully designed features, including an integrated air-cooling system, internal filter mount, and robust CGE dovetail mounting bar.

As an F/2.0 optical system, the 8" RASA allows for shorter exposure times, capturing detail in faint objects quickly. When paired with sensitive cameras and appropriate "live stacking" software, this telescope can provide an almost real-time observing experience, delivering images that are brighter and more detailed than those seen in larger telescopes with the naked eye.

The 8" RASA's relatively short 400mm focal length reduces equatorial tracking demands, often eliminating the need for autoguiding. Despite its lightweight design, this optical tube pairs seamlessly with a wide variety of mounts.

Celestron's new Ultra-Stable Focus System, introduced with the 8" RASA, minimizes lateral movement of the primary mirror when focusing, slewing, or tracking, ensuring easier, more accurate, and more stable focusing.

This telescope is optimized for sensors up to a 22mm diagonal, but performs well with sensors up to 32mm diagonal. It is not compatible with standard DSLR cameras, but works well with the APS-C sized sensors found in many mirrorless cameras.

The 8" RASA's unique optical design, patented under US 2016/0299331 A1, consists of a Schmidt corrector, primary mirror, lens group, and optical window. The lens group contains four elements and utilizes rare-earth elements. Designed to perform over a wider spectral range, from 390-800nm, the 8" RASA ensures more of the light emitted from the astronomical object is sharply focused in the image.

Celestron's 8" RASA, with its advanced features and superior optical performance, is a game-changer for astroimagers, offering a unique blend of portability, affordability, and high-quality imaging.

Celestron CGEM II 800 8" f/2 Rowe-Ackerman Schmidt Astrograph GoTo Telescope Features

  • Flat field free of optical aberrations like field curvature, coma, astigmatism and chromatic aberration across an entire APS-C sensor.
  • NEW Ultra-Stable Focus System six precision sealed ball bearings virtually eliminate image shift.
  • Integrated air cooling system 12V DC MagLev fan reduces cooldown time and provides optimal air flow while filtering out dust.
  • Internal filter mount seamlessly accommodates a Light Pollution Imaging Filter into the optical path.
  • CGE dovetail mounting rail.
  • Performs over a wider spectral range than most telescopes, from 390-800 nm, so more of the light passing through the astrograph is in sharp focus.

Warranty Information

This product has a limited warranty of 24 months for parts and 24 months for labor.

Product Documents

User Manual

Key Features

  • Capture stunning astrophotos with the 8" Rowe-Ackermann Schmidt Astrograph telescope.
  • Enjoy superior optical quality with StarBright XLT coatings for brighter, clearer views.
  • The integrated cooling fan in this telescope reduces thermal currents for optimal imaging.
  • Achieve pinpoint stars to the edge of the field with a large 22 mm image circle.
  • Experience stable, precise tracking with the robust CGEM II GoTo telescope mount.
  • Easily attach your camera with included T-thread and C-thread camera adapters.

What's in the box:

  • 8-inch optical tube assembly
  • 42 mm T-thread camera adapter
  • C-thread camera adapter
  • Fan Battery Pack
  • 2-Year Warranty