Celestron 11" SCT Optical tube, CGE/Losmandy dovetail


Availability: More on the way

This 11" aperture aluminum SCT optical tube has ultra-high transmission Starbright XLT multicoatings and a dovetail for installing it on Celestron CGE and Losmandy G-11 and HGM Titan mounts . . .
Our Product #: C11OTAX
Celestron Product #: 91036-XLT
Recommended Accessories

Product Description

This 24" long aluminum Celestron 11" Schmidt Cassegrain optical tube weighs only 27.5 lbs., making it easy to transport. It has an 11" aperture, a 2800mm focal length, and a focal ratio of f/10. An optional focal reducer is available to bring the focal ratio down to f/6.3 for CCD and 35mm photography. Optical performance is guaranteed to be diffraction-limited.

Advanced high transmission Starbright XLT optical multicoatings are standard equipment. This coatings package includes high reflectivity multilayer aluminum mirrors enhanced with titanium dioxide for high reflectivity, plus a unique combination of magnesium fluoride and hafnium dioxide antireflection coatings on both sides of the Schmidt corrector lens. The corrector lens itself is made of high transmission water white float glass instead of conventional soda lime glass (which has 3.5% lower transmission) used in other telescopes.

Starbright XLT multicoatings visibly increase the contrast on subtle lunar, planetary, and nebula details when compared with a scope with standard multicoatings. They also give you higher light transmission for brighter deep space images and shorter exposure times during CCD and 35mm photography. Across the total visual/photographic spectrum from 400nm to 750nm, independent laboratory tests show the new Starbright XLT coatings are 16% brighter overall than even the original industry-standard Starbright multicoatings.

The optical tube comes with a big 9 x 50mm straight-through achromatic finderscope and mounting bracket. The finder has a wide 5° field of view. It focuses by loosening the trim ring behind the objective lens cell, screwing the lens cell in or out to focus, and tightening the trim ring to lock in the correct focus. Also standard is a removable 1.25" visual back that holds visual accessories such as a star diagonal, tele-extender, etc. A 1.25" prism type star diagonal is also standard, as is a 1.25" 40mm Plössl eyepiece. This eyepiece provides a magnification of 70x. Its field of view is 0.68° across, over a third wider than the full moon. Dust covers for the optics are also supplied.

The optical tube is equipped with a slide bar with a standard 75mm (3") wide dovetail for mounting the tube on Losmandy Style saddles.

Tech Details

Aperture 11"
Focal Length 2800mm
Focal Ratio f/10
Heaviest Single Component 27.5 lbs.
Highest Useful Magnification 560x
Weight 27.5 lbs.
Optical Coatings StarBright/XLT
Resolution 0.41 arc seconds
Telescope Type Schmidt-Cassegrain
Visual Limiting Magnitude 14.7
Warranty 2 years


Review by:
I have had my C11 for a few years now. It is a great scope. I love the optics! I have upgraded to an SCT Crayford focuser and 2" eyepieces. I also switched to a CGE dovetail due to my CGE mount which is also fantastic! The scope takes very nice images using my Nikon DSLR camera either at Prime Focus or Crayford. It is worth the investment. (Posted on 11/2/2018)
Review by:
I have had my C11 for several years now and I feel it is the best choice for me. I wanted the largest mirror I could afford that is light enough for me to carry with my bad back and this SCT is perfect. I do some visual and me and my friends are impressed with the views. But I mostly do imaging with a DSLR and the pictures come out spectacular with my C11. I am very pleased with my Celestron C11 SCT and it is the favorite of all my OTA's. (Posted on 10/16/2018)
Review by:
The C11 has been my main OTA for over 8 years now. Visually it is a great equipment but photographically it is Amazing. I have it converted to Hyperstar compatible and now i can image at anywhere from F2 to F40.
Image quality is very good, it almost doesn't have backfocus problems, you can accomodate almost any imaging equipment with this OTA.
Visually it is a very powerful OTA, and fitted with binoviewers planet watching is breath taking, specially Saturn.
Very good all around Telescope.
Clear skies
Javier. (Posted on 8/4/2017)
Review by:
Fit and finish are exceptional on this OTA. I changed the saddle to accomodate the CGE dovetail as this OTA is too heavy for stability on a Vixen.
There is significant mirror shift when using the focusing knob, so factor in an upgrade to a moonlight or SCT crayford focuser which will add about 3lbs to the weight.
Due to it's aperture, this is very sensative to precise collimation, but star tests very well when seeing is stable. (Posted on 8/4/2017)
How do you rate this product? *

Supplied Accessories

  • Starbright XLT multicoated optics
  • 40mm 1.25" Plössl eyepiece (70x)
  • 1.25" visual back
  • 1.25" prism-type star diagonal
  • 9 x 50mm straight-through finderscope
  • Dust covers
  • Dovetail for mounting on Celestron CGE and Losmandy G-11 and HGM Titan mounts