Schmidt-Cassegrains

Schmidt-Cassegrain telescopes are very popular because they offer a combination of large aperture and relatively small and lightweight package. These are the Jack of all trades in the telescope business. They are moderately well adapted to a wide variety of applications, including lunar, planetary, deep space, and even terrestrial observing.

The market for commercially produced Schmidt-Cassegrains has been dominated by Celestron and Meade Instruments Corporation since the 1980s. Both companies now offer more costly derivatives of the Schmidt-Cassegrain design that reduce an optical aberration known as coma. The latter are primarily designed for for wide-field imaging with larger format CCD cameras; we believe that most visual-only users will be satisfied with the original Schmidt-Cassegrain designs.

  • Celestron CGEM II 1100 SCT
  • Celestron CGEM II 1100 SCT

  • The CGEM II 1100 Schmidt-Cassegrain Telescope features Celestron’s premium StarBright XLT coated optics and the newly redesigned CGEM II computerized equatorial mount. read more...
  • Our price: $3499.00

  • Celestron Nexstar 8SE Advanced Bundle
  • Celestron Nexstar 8SE Advanced Bundle

  • The bundle offering includes the Nexstar 8SE telescope, three X-Cel LX eyepieces, two filters, 7 Ah Power Tank and a red LED night vision flashlight. read more...
  • Our price: $1349.00

  • RRP: $1571.00
    save 14%
  • Celestron NexStar 5SE Computerized Telescope
  • Celestron NexStar 5SE Computerized Telescope

  • The Celestron NexStar 5SE is an ideal computerized beginner telescope having enough aperture to start to introduce you to deep space objects. read more...
  • Our price: $699.00

  • Celestron C6-A-XLT Telescope Optical Tube
  • Celestron C6-A-XLT Telescope Optical Tube

  • The Celestron C6-A-XLT is a compact Schmidt-Cassegrain telescope suitable for both imaging and visual observing. read more...
  • Our price: $429.00

  • Celestron NexStar 6SE Computerized Telescope
  • Celestron NexStar 6SE Computerized Telescope

  • The Celestron NexStar 6SE computerized telescope is a professional solution that will take you beyond the solar system to reveal hundreds of star clusters, galaxies and nebulae. read more...
  • Our price: $799.00

  • Celestron Nexstar 6SE Basic Bundle
  • Celestron Nexstar 6SE Basic Bundle

  • This offering includes the Nexstar 6SE telescope, the #94303 eyepiece and filter kit, 7 Ah Power Tank and a red LED night vision flashlight. read more...
  • Our price: $899.00

  • RRP: $1032.00
    save 13%
  • Celestron Nexstar 6SE Advanced Bundle
  • Celestron Nexstar 6SE Advanced Bundle

  • The Celestron NexStar 6SE Advanced Bundle is one of our most popular offerings for beginning astronomers. read more...
  • Our price: $1049.00

  • RRP: $1171.00
    save 10%
  • Celestron Sky Prodigy 6 Computerized Telescope
  • Celestron Sky Prodigy 6 Computerized Telescope

  • The Celestron SkyProdigy 6 is a revolutionary self-aligning go to telescope that allows beginners to see planets and other objects on their first night out. read more...
  • Our price: $999.00

  • Celestron Nexstar Evolution 6
  • Celestron Nexstar Evolution 6

  • Celestron Nexstar Evolution 6-inch Schmidt-Cassegrain Telescope with integral WiFi networking and Lithium ion battery. read more...
  • Our price: $1299.00

  • Celestron Advanced VX 6-inch Schmidt-Cassegrain Telescope
  • Celestron Advanced VX 6-inch Schmidt-Cassegrain Telescope

  • Celestron Advanced VX 6 SCT is the most affordable Schmidt-Cassegrain telescope available on a Go To German equatorial mount. read more...
  • Our price: $1169.00

  • RRP: $1299.00
    save 10%
  • Celestron C8-A XLT (CG-5) Optical Tube Assembly
  • Celestron C8-A XLT (CG-5) Optical Tube Assembly

  • Celestron C8-A XLT Schmidt-Cassegrain optical tube assembly with Vixen style dovetail, 6x30 optical finder, 1.25” star diagonal and 25mm Plossl eyepiece. read more...
  • Our price: $975.00

  • Celestron C8-A XLT (CGE) Optical Tube Assembly
  • Celestron C8-A XLT (CGE) Optical Tube Assembly

  • Celestron C8-A optical tube assembly with Lodmandy style (CGE) dovetail, 6x30 optical finder, 1.25-inch star diagonal and 25mm Plossl eyepiece. read more...
  • Our price: $975.00

  • Celestron EdgeHD 800 (CG-5) Optical Tube Assembly
  • Celestron EdgeHD 800 (CG-5) Optical Tube Assembly

  • Celestron 91031-XLT EdgeHD 800 OTA equipped with Vixen style dovetail bar produces pinpoint star images all the way to the edge of the field. read more...
  • Our price: $1149.00

  • Celestron EdgeHD 800 (CGE) Optical Tube Assembly
  • Celestron EdgeHD 800 (CGE) Optical Tube Assembly

  • Celestron 91030-XLT EdgeHD 800 OTA equipped with Losmandy style dovetail bar produces pinpoint star images all the way to the edge of the field. read more...
  • Our price: $1149.00

  • RRP: $1299.00
    save 12%
  • Celestron NexStar 8SE Computerized Telescope
  • Celestron NexStar 8SE Computerized Telescope

  • The Celestron NexStar 8SE computerized telescope is the lightest, most portable and best value available in an 8" Go-To Schmidt-Cassegrain telescope. read more...
  • Our price: $1199.00

  • Celestron Nexstar 8SE Basic Bundle
  • Celestron Nexstar 8SE Basic Bundle

  • This offering includes the Nexstar 8SE telescope, the #94303 eyepiece and filter kit, 7 Ah Power Tank and a red LED night vision flashlight. read more...
  • Our price: $1249.00

  • RRP: $1432.00
    save 13%
  • Celestron Nexstar Evolution 8
  • Celestron Nexstar Evolution 8

  • The Celestron Nexstar Evolution 8-inch Schmidt-Cassegrain Telescope features integral WiFi and a powerful Lithium ion battery. read more...
  • Our price: $1699.00

  • Celestron NexStar Evolution 8 HD with StarSense
  • Celestron NexStar Evolution 8 HD with StarSense

  • The Nexstar Evolution 8 EdgeHD Telescope from Celestron features integral Starsense auto alignment, WiFi and internal Lithium ion battery. read more...
  • Our price: $2299.00

  • Celestron Advanced VX 8-inch Schmidt-Cassegrain Telescope
  • Celestron Advanced VX 8-inch Schmidt-Cassegrain Telescope

  • Celestron Advanced VX 8 SCT combines the iconic 8-inch Schmidt-Cassegrain with a lightweight German equatorial mount that is suitable for photography. read more...
  • Our price: $1529.00

  • RRP: $1699.00
    save 10%
  • Celestron Advanced VX 8" EdgeHD Telescope
  • Celestron Advanced VX 8" EdgeHD Telescope

  • The Advanced VX 8 EdgeHD from Celestron offers exceptional value as an entry level astro-imaging package. read more...
  • Our price: $1889.00

  • RRP: $2099.00
    save 10%
  • Celestron CGEM II 800 SCT
  • Celestron CGEM II 800 SCT

  • The CGEM II 800 Schmidt-Cassegrain Telescope features Celestron’s premium StarBright XLT coated optics and the newly redesigned CGEM II computerized equatorial mount. read more...
  • Our price: $2299.00

  • Celestron CGEM II 800 EdgeHD
  • Celestron CGEM II 800 EdgeHD

  • CGEM II 800 HD combines Celestron's newly redesigned CGEM II computerized equatorial mount with its acclaimed EdgeHD optical system. read more...
  • Our price: $2599.00

  • Celestron CGX 800 SCT
  • Celestron CGX 800 SCT

  • The CGX Equatorial 800 SCT combines the innovative CGX German Equatorial mount with the traditional 8-inch Schmidt-Cassegrain optical tube. read more...
  • Our price: $2899.00

  • Celestron CGX 800 HD
  • Celestron CGX 800 HD

  • The CGX 800 HD combines Celestron's EdgeHD 800 optical tube with the CGX German equatorial mount. read more...
  • Our price: $3199.00

  • Celestron CPC 800 GPS (XLT) Computerized Telescope
  • Celestron CPC 800 GPS (XLT) Computerized Telescope

  • The Celestron CPC 800 GPS packs a lot of aperture into a package that is very portable and easy to use. read more...
  • Our price: $1999.00

  • Celestron CPC Deluxe 800 HD Computerized Telescope
  • Celestron CPC Deluxe 800 HD Computerized Telescope

  • Celestron CPC Deluxe 800 HD combines the innovative EdgeHD optics with the convenience of a fork mounted telescope. read more...
  • Our price: $2399.00

  • Meade 8" LX90 ACF Telescope
  • Meade 8" LX90 ACF Telescope

  • Meade's most popular Schmidt-Cassegrain telescope features Advanced Coma-Free Optics provide pinpoint stars all the way to the edge of field. read more...
  • Our price: $1799.00

  • Meade 8" LX200-ACF (f/10) Telescope
  • Meade 8" LX200-ACF (f/10) Telescope

  • The Meade 8" LX200-ACF offers greater stability and more advanced features than the comparable Meade LX90 model. read more...
  • Our price: $2699.00

  • Celestron C9 1/4-A (XLT) (CG-5) Optical Tube Assembly
  • Celestron C9 1/4-A (XLT) (CG-5) Optical Tube Assembly

  • Celestron C9-1/4 optical tube assembly with Vixen style dovetail, 6x30 optical finder, 1.25-inch diagonal and 25mm Plossl eyepiece. read more...
  • Our price: $1378.00

  • Celestron C9 1/4-A XLT (CGE) Optical Tube Assembly
  • Celestron C9 1/4-A XLT (CGE) Optical Tube Assembly

  • Celestron C9-1/4 optical tube assembly with Losmandy style (CGE) dovetail, 6x30 optical finder, 1.25-inch diagonal and 25mm Plossl eyepiece. read more...
  • Our price: $1368.00

  • Celestron EdgeHD 925 Telescope Optical Tube
  • Celestron EdgeHD 925 Telescope Optical Tube

  • This update to the highly acclaimed Celestron C 925 designed to produce aberration-free images across a wide field of view. read more...
  • Our price: $1999.00

  • RRP: $2299.00
    save 13%
  • Celestron Advanced VX 9.25-inch Schmidt-Cassegrain Telescope
  • Celestron Advanced VX 9.25-inch Schmidt-Cassegrain Telescope

  • The Advanced VX 9.25 SCT from Celestron gathers 33% more light than the smaller 8-inch models, which is particularly beneficial for deep space observing. read more...
  • Our price: $1979.00

  • RRP: $2199.00
    save 10%
  • Celestron CGEM II 925 SCT
  • Celestron CGEM II 925 SCT

  • The CGEM II 925 Schmidt-Cassegrain Telescope features Celestron’s premium StarBright XLT coated optics and the newly redesigned CGEM II computerized equatorial mount. read more...
  • Our price: $2599.00

  • Celestron CGEM II 925 EdgeHD
  • Celestron CGEM II 925 EdgeHD

  • CGEM II 925 HD combines Celestron's newly redesigned CGEM II computerized equatorial mount with its acclaimed EdgeHD optical system. read more...
  • Our price: $3499.00

  • Celestron Nexstar Evolution 925
  • Celestron Nexstar Evolution 925

  • Celestron's legendary 9.25-inch Schmidt-Cassegrain telescope finally goes ultra portable with the Nexstar Evolution 925. read more...
  • Our price: $2199.00

  • Celestron CGX 925 SCT
  • Celestron CGX 925 SCT

  • The CGX Equatorial 925 SCT combines the innovative CGX German Equatorial mount with the traditional 9-1/4 inch Schmidt-Cassegrain optical tube. read more...
  • Our price: $3199.00

  • Celestron CGX 925 HD
  • Celestron CGX 925 HD

  • Celestron CGX 925 HD combines Celestron's all-new state of the art CGX computerized equatorial mount with its established and acclaimed EdgeHD optical system. read more...
  • Our price: $4099.00

  • Celestron CGX-L 925 SCT
  • Celestron CGX-L 925 SCT

  • The Celestron CGX-L 925 SCT combines the legendary 9-1/4 inch Schmidt-Cassegrain with Celestron's largest and most capable German equatorial mount. read more...
  • Our price: $4499.00

  • Celestron CGX-L 925 EdgeHD
  • Celestron CGX-L 925 EdgeHD

  • The Celestron CGX-L 925 EdgeHD combines premium 9-1/4 inch EdgeHD optics with Celestron's largest and most capable German equatorial mount. read more...
  • Our price: $5399.00

  • Celestron CPC 925 GPS (XLT) Computerized Telescope
  • Celestron CPC 925 GPS (XLT) Computerized Telescope

  • The Celestron CPC 925 provides more aperture than its 8-inch sibbling at only a small increase in cost and weight. read more...
  • Our price: $2499.00

  • Celestron CPC Deluxe 925 HD Computerized Telescope
  • Celestron CPC Deluxe 925 HD Computerized Telescope

  • Celestron CPC Deluxe 925 HD offers more aperture than its 8-inch sibbling with only modest gains in cost and weight. read more...
  • Our price: $3199.00

  • Meade 10" LX90 ACF Telescope
  • Meade 10" LX90 ACF Telescope

  • The Meade 10" LX90-ACF offers large aperture without the large price tag and is a highly capable telescope for visual use. read more...
  • Our price: $2399.00

  • Meade 10" LX200-ACF (f/10) Telescope
  • Meade 10" LX200-ACF (f/10) Telescope

  • The popular 10" Meade LX200-ACF is one of the largest fork mounted telescopes that can still be easily set up by one man. read more...
  • Our price: $3499.00

  • Meade 10" LX600 ACF Telescope
  • Meade 10" LX600 ACF Telescope

  • The 10-inch LX600 features f/8 Advanced Coma Free optics combined with Meade's innovative Starlock technology. read more...
  • Our price: $4699.00

  • Celestron C11-A XLT (CG-5) Optical Tube Assembly
  • Celestron C11-A XLT (CG-5) Optical Tube Assembly

  • This version of the Celestron C11 is fitted with a Vixen style dovetail for use with smaller mounts, such as the Advanced VX. read more...
  • Our price: $2315.00

  • Celestron C11-A XLT (CGE) Optical Tube Assembly
  • Celestron C11-A XLT (CGE) Optical Tube Assembly

  • This version of the classic Celestron C11 is fitted with a Losmandy style dovetail compatible with larger mounts, such as the CGEM DX. read more...
  • Our price: $2337.00

  • Celestron EdgeHD 1100 Telescope Optical Tube
  • Celestron EdgeHD 1100 Telescope Optical Tube

  • Celestron EdgeHD 1100 was designed to reduce off-axis star coma and give flat field with pinpoint stars all the way to the edge of the field. read more...
  • Our price: $2999.00

  • RRP: $3399.00
    save 12%
  • Celestron Advanced VX 11-inch Schmidt-Cassegrain Telescope
  • Celestron Advanced VX 11-inch Schmidt-Cassegrain Telescope

  • The Advanced VX 11 SCT is thew most cost effective way to purchase an eleven inch Schmidt-Cassegrain telescope. read more...
  • Our price: $2499.00

  • RRP: $2799.00
    save 11%

Schmidt-Cassegrain Telescopes for Sale

Schmidt-Cassegrain telescopes are some of the most popular pieces of equipment on the market, favored for their large aperture in a relatively small, lightweight package. Schmidt-Cassegrain telescopes are reflecting telescopes, using a catadioptric design with both mirrors and lenses to minimize aberrations. The result is a relatively compact telescope that is well-adapted to a wide variety of applications, including lunar, planetary, deep space and even terrestrial observing. They’re a Jack of all trades in the telescope business.

Schmidt-Cassegrain telescopes, also called SCTs, use the following components to produce a quality image:

  • Schmidt Corrector Lens: Also known as a corrector plate, this lens is at the front end of an SCT and is where light passes through to enter the telescope. This Schmidt corrector lens is flat with a slight aspheric curve to correct the spherical aberration caused using spherical mirrors in the telescope.
  • Concave Primary Mirror: This is the light that passes through the corrector lens and is reflected by a concave primary mirror at the back of the scope, close to the eyepiece. This concave mirror focuses the light toward the front of the telescope. Usually, these primary mirrors have a focal length around twice the diameter of the mirror. For example, a Celestron 8-inch CPC Schmidt-Cassegrain telescope would have an 8-inch primary mirror with a focal length of 16 inches.
  • Convex Secondary Mirror: The primary mirror reflects light onto a convex secondary mirror close to the front of the telescope. This not only reflects the light back toward the primary mirror but the convex curvature of this mirror also effectively magnifies the focal length of the telescope, allowing the telescope to act much longer than it is. Typically, this magnification factor is around 5x. Following the previous example, this means that an 8-inch telescope with a primary mirror that produces a focal length of 16 inches would have an effective focal length of 80 inches, ten times the diameter of the primary mirror.
  • Eyepiece:  The light reflected by the convex secondary mirror travels back through the telescope, via a hole in the primary mirror. This light then focuses at the rear end of the scope, where an eyepiece is placed for visual observing. A CCD camera can also be placed there for astrophotography.

Skies Unlimited offers quality Schmidt-Cassegrain telescopes for sale, as well as quality expertise and advice to help you choose the best model for your needs. Founded in 2004 by real amateur astronomers, we strive to provide our customers with the knowledge and equipment they need to thrive in their astronomy experience. That’s why we keep a team of active amateur astronomers on staff to help you with their personal and professional expertise. No matter what you need, from beginner’s advice to advanced equipment recommendations, we’re here to help.

Learn More Today

Whether you want to place an order for a Celestron 11-inch CPC Schmidt-Cassegrain telescope, ask how that model differs from our Celestron 14-inch Schmidt-Cassegrain telescope or learn more about our free shipping offers, you can count on Skies Unlimited. Call Skies Unlimited today or visit our store located just outside of Pottstown, Pa., to speak with one of our experienced team members.


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