Celestron C9.25 XLT Adv
This OTA has been replaced by 91027: https://www.grovers.biz/cassegrain/90-2449-celestron-c925-xlt-optical-tube-assembly-cge-050234102797.html
Warranty: 2 years
Celestron Schmidt-Cassegrain Optical Tube Assemblies (OTA) are available individually for use with your favourite mount. Each OTA is made to the same exacting standards as those used on all our high quality telescopes.
All optical surfaces are coated with Celestron’s high efficiency StarBright® multi-layered coating group. These tube assemblies are equipped with the same dovetail mounting bar used on the CGE and Advanced Series for easy attachment to a variety of popular mounts.
• 9.25" Schmidt-Cassegrain Optical Tube Assembly
• Aluminum Optical Tube
• Celestron's premium StarBright XLT coatings
• 2350 mm focal length (f/11)
• 25 mm eyepiece included (94x)
• Visual back allows for use with 1.25" accessories
• 6x30 finderscope to help accurately find objects
• Star diagonal provides more comfortable viewing position when observing objects that are high in the sky
• Includes dovetail rail compatible with CG-5 Advanced Series mount
OPTICAL DESIGN : Schmidt-Cassegrain
DOVETAIL COMPATIBILITY : CG-5 Mount
APERTURE: 234.95 mm (9.25 in)
FOCAL LENGTH : 2350 mm (92.52 in)
FOCAL RATIO : 10
FINDERSCOPE : 6x30
OPTICAL TUBE : Aluminum
EYEPIECE 1 : 25 mm (0.98 in)
MAGNIFICATION 1 : 94 x
STAR DIAGONAL : 1.25
OPTICAL COATINGS : StarBright / XLT
SECONDARY MIRROR OBSTRUCTION : 3.35 in (85.09 mm)
SECONDARY MIRROR OBSTRUCTION BY AREA : 13.1 %
SECONDARY MIRROR OBSTRUCTION BY DIAMETER : 36.2 %
OPTICAL TUBE LENGTH : 22 in (558.8 mm)
OPTICAL TUBE WEIGHT : 20 lb (9.07 kg)
The C9¼ as it was originally known became the Celestron SCT with the cult following. The reason behind this was due to its photographic performance. Its slightly longer primary focal length and lower power secondary than other f/10 SCTs, meant that the diffraction limited field of this telescope was slightly larger than if it had been a standard configuration f/10. In simple terms, it had slightly less off-axis coma, and so was favoured by deep-sky astrophotographers.
Today it is still the same, although the Edge HD SCTs have taken over as the most desirable imaging SCTs. The 9.25 is the most popular imaging standard SCT Celestron produce. It has a visual and photographic performance advantage over the C8, and although a little longer and heavier, it is still compact and very portable, and crucially, not too heavy for budget German equatorial mounts such as the CG5 and EQ5. For all round photo-visual performance, practicality and manageability, the 925 is still the pick of the Celestron SCTs for astronomy and imaging.
Photographically it is a diffraction limited 2350mm f/10 telephoto, a 4700mm f/20 telephoto by adding a 2X Barlow, or a 1480.5mm f/6.3 telephoto by adding the Celestron f/6.3 focal reducer lens.
Budget for the SCT t-adapter, the f/6.3 focal reducer, a 2" star diagonal so 2" eyepieces can be used, a Neutral Density filter or Polariser for the moon, the Celestron dewshield, and the Baader UHC and Oxygen III filters.
- Optical Design
- Schmidt Cassegrain
- 9.25 inch
- Focal Length
- 2350 mm
- Focal Ratio
- Optical Coatings
- Starbright XLT Coating
- Optical Tube Length (mm)
- 22 inch