Used TPO 14" f/8 Ritchey-Chretien Truss Tube Telescope - 11540 - SOLD

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  • $4,599.00
  • Regular price $5,875.00

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  • This is a demo scope in excellent condition*
  • Aperture: 14-inches
  • Focal Ratio: F/8
  • Focal Length: 2845 mm
  • Great Value imaging telescope



Used TPO 14" f/8 Ritchey-Chretien Truss Tube Telescope - 11540 - SOLD

11540: In 1910, American optician and astronomer George Willis Ritchey & French astronomer Henri Chretien designed a specialized Cassegrain that would later become the telescope of choice for many observatories and professionals around the world. The Ritchey-Chretien astrograph has many benefits that make this design appealing to anyone who is serious about astrophotography or imaging. Here are a few of those benefits:

  • Good-bye Coma: An RC has virtually no coma (stars look like little comets around the edges of the field), which means there will be greater image quality across a wider field of view.
  • No Chromatic Aberration: Because a Ritchey-Chretien does not use lenses or corrector plates, the design does not suffer from chromatic aberrations, or false color. If you've ever looked through an achromatic refractor (non-APO), you will have seen chromatic aberration.
  • No Spherical Aberration: The use of hyperbolic mirrors for both the primary and secondary removes the problem of spherical aberration from this optical system, an optical effect caused when light rays do not all come to focus at the same point, resulting in an image that is not in perfect focus.

Optical Highlights: This Third Planet Optics (TPO) Ritchey Chretien telescope has 14-inch (355.6 mm) of aperture and a focal length of 2845 mm . The concave hyperbolic primary and convex hyperbolic secondary are made from low expansion quartz, and finished with a scratch-resistant highly reflective 99-percent dielectric coating for great contrast. The primary mirror is fixed in place in a metal mirror cell, and the secondary resides in a metal housing that can be collimated.

Carbon Fiber Truss Tube Design:

Lightweight yet strong carbon fiber truss tubes have low thermal expansion characteristics. Shifts in focus due to temperature changes are minimized because of this design. The trusses are also designed to flex equally, keeping the optics in collimation regardless of the position of the telescope.

Cooling Fans: The 14-inch Ritchey has three small cooling fans in the rear cell that help cool the inside of the tube down and bring it to ambient temperature so that you can start imaging sooner! The fans are powered by an external battery pack. This battery holder accepts 8-AA batteries (sold separately).

A Fixed Primary Eliminates Image Shift Schmidt-Cassegrain & Mak-Cassegrain telescopes achieve focus by moving the primary mirror back and forth inside the optical tube assembly, and this movement can cause image shift. While manufacturers have done a pretty good job of minimizing image shift on their telescopes, a movable mirror makes it almost impossible to eliminate it completely. The Ritchey-Chretien has a primary that is fixed in place, removing the possibility of image shift and also the job of collimating the primary.

Two D Style Losmandy Dovetails Included Talk about versatility! Two Losmandy-style dovetails are attached to the truss tube support rings so that they ride at the top of the scope as well as at the bottom.

Long Back Focus of 288 mm allows you to mount lots of imaging gear!



Aperture356 mm (14.02")
CoolingFans/ Includes 3 small
Focal Length2845mm
Focal Ratiof/8
Mounting PlatesD Plate Dovetail/ Two
Optical DesignRitchey Chretien


  • TPO 14-Inch RC truss tube optical assembly
  • There is no focuser included with this OTA



Ask a Question
  • In thinking thru imaging with this scope I imagine the combined weight of the imaging train will require weights at the front of the tube to get correct balance. Is this assessment correct? Do you sell these weights?

    In most cases, additional declination weights are not needed with the 14RC-TT because the center of balance stays over the dovetail as long as you don't add more than about 15-20 lbs to the rear of the scope. The smaller smaller 10" RC might need Losmand

  • Do you have a focal reducer and/or field flattener available for this telescope? If so, what are the prices?

    We do offer several options of reducers and flatteners for this telescope and all of them are at various price points. To determine which one would best match your equipment, Please give a call at 1-800/483-6287 or email us at

  • Could you please tell me what the difference is between this scope the ETX90 AT and the ETX90 Observer is?

    The Meade EXT90AT is the basic version with the tube fixed to the forks. The ETX90 Observer has a cradle that allows removal of the tube (to act as a telephoto lens or spotting scope) and comes with a hard carry case.

  • What is the useful magnification? How is the image quality compared the commercial SCT's made by Meade and Celestron>

    The useful magnification depends on seeing, but using the 50x per inch rule you could theoretically use up to 700x magnification. Air turbulence will usually limit you to 200-400x, depending on the night and conditions. This telescope is an RC astrograp

  • I interested this OTA, and i will use take a picture. and so, i will add moto focuser, Is this possible before with puchase

    There are several options to add motorized focus to this telescope, but options are limited with the stock focuser. Please contact us at the store and we can assist you in choosing the right motorized focuser for this telescope.

  • I need more details to decide whether to purchase 12" or 14" TPO Truss Tube OTA: (i) physical dimension comparison to determine whether 14" will fit in ShyShed POD; (ii) does 12" also include built in tip-tilt adapter; (iii) apples-to-apples weight compar

    The 14" is 20.5" across at the rear ring (21.5" including dovetails) and 39" long with no focuser or threaded attachment. It weighs 65 lbs in this configuration. The 12" is 17.5"/18.5" at the rear ring and just a bit over 33" long. The base weight of t

  • What mount would you recommend for this scope - trying to get a handle on the total cost.

    With a base weight on this scope of approximately 65 lbs and a typical imaging load including camera, filter wheel, focuser, extensions and accessories of approximately 80-85 lbs, we would generally only recommend mounts with stated capacities of at least

  • what is the difference between the Astro-Tech 14" f/8 truss tube Ritchey–Chrétien optical tube and the TPO 14" f/8 RC Truss Tube OTA ? Also can a optec 2icnch tcf focuser be used with either item? Thanks jim

    Both scopes can be used with a TCFS or TCFSi. Depending if you are putting a big camera on the back of the scope, It may be worth considering a TCFS3. The main difference between these scopes is the rigidity of the tubes and the TPO having a built in tip

  • What is the BOX SIZE of this telescope? Thanks!

    Marcelo, The box size is 52" x 40" x 32" and weighs 100 lbs. It's shipped on a pallet. For shipping information, please give me a call at 800-483-6287 or contact me at and I will help you. Thanks, Steve

  • What is the image circle diameter at focus?

    Cameras up to 30mm diagonal (APS-C format) can be used without correctors before field curvature intrudes, but with the optional Teleskop Service RC corrector (TS-RCKORREKTOR - $309), the image circle is increased to 45mm and will work with full 35mm form

  • What is the WEIGHT of this telescope in pounds? Thank you?

    The TPO 14" Truss scope is 65 lbs without the focuser or extension rings attached.