The EdgeHD 9.25 Optical Tube Assembly from Celestron features an Aplanatic Schmidt-Cassegrain optical system. This compound, or catadioptric, light-path employs a combination of mirrors and lenses that offer a large high-resolution aperture, a shorter tube length, and enhanced portability. This telescope has a 9.25" aperture, a focal length of 2350mm, and a focal ratio of f/10.
The EdgeHD optical system consists of a zero power corrector plate, a spherical primary mirror, and a secondary mirror along with a set of field flattening lenses integrated into the baffle tube. The optics of an EdgeHD telescopes feature StarBright XLT multi-layer coatings on the primary and secondary mirrors for increased reflectivity. The corrector is also fully coated to ensure enhanced anti-reflection characteristics.
The EdgeHD optical system is designed to optimise an image circle with a 42 mm diameter around the centre of the field of view. This circle completely covers the diagonal of a full-frame DSLR camera or a standard 35mm film frame. As such, it extends significantly beyond the diagonal of APS-C sensors and the smaller chips used in specialised astrophotography CCD cameras. Further refinement of the system's imaging capabilities is managed via mirror tension clutches that help support the primary mirror and minimise its lateral movement. This enhancement is particularly important to astrophotographers as it significantly improves the system's stability and imaging clarity.
This OTA comes with a very useful 9x50 finderscope fitted to its exterior. Due to its wider field of view, this ancillary optic can offer assistance in locating objects to view with the main scope.
Normal image orientation for the EdgeHD design is upside-down and reversed. The 2.0" diagonal inverts this image so it is right-side-up, but reversed. This diagonal directly accepts 2.0" eyepieces, and a 1.25" eyepiece adapter is included.
Also included in this package is Celestron's Axiom LX 23 mm eyepiece. This ocular is ideal for deep-space viewing - its wide field of view produces a feeling of being surrounded by the viewing experience.
- Aperture: 9.25"
- EFL: 2350 mm, f/10
- Aplanatic Schmidt-Cassegrain system for aberration-free imaging
- Premium StarBright XLT coatings for enhanced light transmission
- Aluminium tube
- Mirror support knobs reduce image shift
- Filtered tube vents release hot air from behind the primary mirror
- Dovetail rail: included in package - compatible with Celestron's CGE mount
- Fastar compatible: equipped with a removable secondary mirror for ccd imaging
- Angle of view: 5.8°
- Assists in locating objects
- All mounting hardware is included in kit
Axiom LX 23mm Wide Angle Eyepiece
- AAoV: 82°
- Eye Relief: 17 mm
- Magnification: 102x with 9.25" EdgeHD
- Accepts Celestron's 2.0" thread-in filters
- Parfocal design allows for fast switching of eyepieces
- Retractable eyecup provides ultra-low profile for eyeglass wearers
- Accepts 2.0" eyepieces
- 1.25" eyepiece adapter included
- Image orientation: right-side-up, laterally reversed
- StarBright XLT multi-layer coatings enhance light transmission
- Improved brass clamping ring provides a secure no-mar connection
|Optical Design||Aplanatic Schmidt-Cassegrain|
|Aperture||9.25" / 235 mm|
|Focal Length||2350 mm / 92.52"|
|Resolving Power||Rayleigh: 0.59 arc/sec |
Dawes: 0.49 arc/sec
|Theoretical Minimum and Maximum Magnification||Min: 34x |
|Dovetail Plate||Included, compatible with CGE mount|
|Eyepiece Barrel Diameter||2.0" diagonal w/1.25" adapter|
|Optical Tube Dimensions||Length: 22.0" / 55.8 cm|
|Weight||21.0 lb / 9.53 kg|