Outfitted with an over-sized aperture, long effective focal length, and their proprietary StarBright XLT optical coatings, the Celestron C11-A XLT 11" f/10 Schmidt-Cassegrain Telescope provides power and portability. The coating system consists of anti-reflection coatings on the corrector plate, highly reflective index mirror coatings, and low-absorption/high-transmission glass components to ensure that the maximum amount of light is gathered and transmitted to the user's eye. This system ensures bright and clear high-contrast images with accurate color rendition across the entire visual spectrum without visible distortion at the edges. Celestron includes a standard 1.25" visual back to accept eyepieces and accessories such as the 40mm eyepiece and 90° diagonal supplied with the optical tube assembly (OTA). This OTA is offered here without a mount or tripod for users who already have a support system—just ensure the mount's payload capacity exceeds 27.5 pounds to safely carry the weight and that the mount has a Losmandy-style saddle to match the OTA's CGE mounting plate.

11" Schmidt-Cassegrain OTA    2800mm Focal Length, f/10 Focal Ratio    StarBright XLT Optical Coatings    Motorized Computer-Controlled EQ Mount    40,000+ Database, User-Defined Objects    Multiple Alignment Procedures    Backlash Compensation, Permanent PEC    40mm Eyepiece, 90° Diagonal    9x50 Finderscope with Bracket    2" Steel Adjustable Tripod with Tray

• 11" (279.4mm) aperture
• f/10 focal ratio
• 2800mm effective focal length
• Schmidt-Cassegrain design optical path
• StarBright XLT optical coatings
• Resolution: 0.5 arcsec (Rayleigh); 0.42 arcsec (Dawes)
• Secondary mirror obstruction: 3.75" (95 mm); 34% by diameter; 12% by area

• Maximizes light transmission through optical path
• Improves color rendition, contrast, sharpness, resolution, and brightness
• Broadband system provides flat wavelength transmission across the entire visual spectrum
• Multi-layer mirror coatings with layers of aluminum, SiO2 (quartz), and TiO2 (titanium dioxide)
• Multi-layer anti-reflective corrector plate coatings with layers of MgF2 (magnesium fluoride) and HfO2 (hafnium dioxide); hafnium has a wider band-pass than the commonly used titanium
• High-transmission water white glass corrector plate limits light loss due to internal absorption

• Optical tube only—mount and tripod required for proper use
• Supplied with CGE dovetail plate, which is compatible with Losmandy-style saddles
• Mount must have a payload capacity of over 27.5 pounds to safely support the OTA

• Visual back:
• Standard threads for Schmidt-Cassegrain telescope optical tubes
• 1.25" holder accepts 1.25" eyepieces and accessories

• Eyepiece:
• 1.25"-diameter barrel
• Accepts most 1.25" astronomical filters
• 40mm focal length produces 70x magnification

• Diagonal:
• 1.25"-diameter barrel
• 90° angle places head in comfortable viewing position when scope is aimed at or near the zenith
• Star diagonal corrects view horizontally, but not vertically

• Finderscope:
• 9x magnification
• 50mm aperture
• Mounting bracket included

Related Questions and Answers

Q: 1. Does the Celestron Illuminated RACI Finder Scope fit on the 9.25 OTA?

A: Yes, the Celestron C9 1/4-A XLT 9.25" f/10 Schmidt-Cassegrain Telescope (OTA Only, CGEM Dovetail) is compatible with the Celestron RACI finder scope: https://bit.ly/3HnwhMC

Q: 2. Can you use a 2" visual back and 2" eyepieces?

A: The iOptron Photron 150mm f/9 Ritchey-Chrétien Catadioptric Telescope (OTA Only) BH #IO6111 • MFR #6111optical tube is outfitted with a standard 1.25" visual back to make it easier to find eyepieces, accessories, and imaging gear. For visual observations, a 1.25" star diagonal is included along with a 40mm Plössl eyepiece that yields 51x magnification. You would need to reoutfit it with a 2" diagonal and eyepiece

Q: 3. Can the Celestron C9 1/4-A XLT be upgraded to a 2 inch focuser and 90 degree Eyepiece? If so what are the recommendations and part numbers? Thanks

A: The Explore Scientific APO EDT Series Rack & Pinion Focuser (2") BH #EXFOCEDAPORP • MFR #FOCEDAPO-RP should work. There is no 90 degree eyepiece.There is a 90 degree diagonal.

Q: 4. 1. Can you attach a phone to take pictures? 2. What is an economic mount we can get for this?

A: To attach a smartphone to the Celestron EdgeHD CGE 8" f/10 Aplanatic Schmidt-Cassegrain Telescope (OTA Only) you can use this adapter: https://bhpho.to/3bqiPIf. The Celestron advanced VX Mount would be recommended for the Celestron EdgeHD CGE 8" f/10 Aplanatic Schmidt-Cassegrain Telescope (OTA Only): https://bhpho.to/3FW892P

Q: 5. is the scope 100% no doubts in perfect working condition? given you put 8+ in the condition state...

A: The glass and mirrors on the Celestron EdgeHD 14" f/11 Aplanatic Schmidt-Cassegrain Telescope (OTA Only) Used Cat #2560494 • MFR #91060-XLT are clean. Maybe some blemishes on the metal surface.. Used equipment still has the 30 day B&H return policy.

Q: 6. Does it come with a polar scope?

A: It comes with a 6x30 Finderscope 1.25" 90° Star Diagonal

Q: 7. Does it need a second counterweight to do astrophotography with a dslr maybe an autotracker?

A: It depends on the weight of your camera body. If your camera body is over 2 lbs. I would suggest additional counter balance weights.

Q: 8. is this a used telescope or brand new one?

A: Celestron EdgeHD 14" f/11 Aplanatic Schmidt-Cassegrain Telescope (OTA Only) BH #CE91060XLT • MFR #91060-XLT NEW direct from Celestron In stock at B&H

Q: 9. Can I attach a Nikon Z9 with appropriate adapters or is it too heavy?

A: The Celestron CGEM II 800 8" f/10 EdgeHD Aplanatic SCT GoTo Telescope can be used with a Nikon Z9 camera with this Neewer adapter: https://bhpho.to/48kjNBq

Q: 10. Is the dovetail compatible with an Orion Starseeker IV mount?

A: The Celestron C6-A-XLT CG-5 6" f/10 Schmidt-Cassegrain Telescope has a standard Vixen dovetail rail so it will fit any brand mount that uses a Vixen dovetail. We do not sell Orion brand mounts but based on the specs on Orion's website, the Celestron telescope not will fit. Plus the Orion mount only supports 13 pounds. The Celestron scope weighs 10. I would recommend using a stronger mount for the Celestron such at this scope and mount kit: https://bhpho.to/2YyNBqG