TPO 6" f/9 Ritchey-Chretien Reflecting OTA Telescope

ITEM #
OS-6RC
  • Sale
  • Regular price $399.00
  • TPO 6" f/9 Ritchey-Chretien Reflecting OTA Telescope

    • Sale
    • Regular price $399.00
    • ITEM #
      OS-6RC

    4
    Free Shipping
    Already have gear? Trade it in for cash or new equipment.

    TPO 6" f/9 Ritchey-Chretien Reflecting OTA Telescope

    Based on George Willis Ritchey and Henri Chretien optical design, the TPO 6" f/9 Ritchey-Chretien Reflecting OTA Telescope is a versatile astrograph that can also be used for visual use. The RC Design contains a Hyperbolic shaped primary and secondary mirror to eliminate coma, chromatic aberrations, and spherical aberrations. For expert or professional astronomers interested engaged in scientific study, this telescope makes an excellent choice for astrometric measurements.

     

    TPO 6" f/9 Ritchey-Chretien Reflecting OTA Telescope Highlights

    • No Chromatic Aberration: a Ritchey-Chretien doesn't use lenses or corrector plates, the design doesn’t suffer from chromatic aberrations ( false color).
    • Goodbye Coma: an RC has virtually no coma
    • No Spherical Aberration: The use of hyperbolic mirrors for both the primary and secondary removes the problem of spherical aberration.
    • Long Back Focus: 150mm from the focuser or 235mm from the rear thread allows you to mount lots of imaging gear.
    • Fixed Primary: eliminates image-shift/mirror-flop and removes the need to collimate the primary mirror.
    • Knife Edge Baffling System: computer designed and optimized baffle system prevent internal reflections and boost contrast.

     

    Specifications with Optional Reducers

      • Product Number: OS-FRRC-75
      • Effective Focal Length: 1028mm
      • Effective Focal Ratio: f/6.8
      • Resulting Image Circle: 15mm
      • Reducer Backfocus: 80mm
    • Reducer: Astro-Physics CCD Focal Reducer for f/9-f/18 Telescopes
      • Product Number: AP-CCDT67
      • Effective Focal Length: 918mm-1069mm
      • Effective Focal Ratio: f/6.-f/7
      • Resulting Image Circle:  29.5mm-34.3mm
      • Reducer Backfocus: 67mm-101mm
      • This reducer has different effects based on the spacing between the camera and the reducer. If you need assistance figuring this out, you can refer to the Astro-Physics 27TVPH and CCDT67 Compression & Coverage Document or contact us.

     

    Accessories Included in the Box

     Here are the adapters and accessories included from TPO when you purchase the TPO 6" f/9 Ritchey-Chretien Reflecting OTA. They are listed in the same order that you would attach them to the rear threads of the telescope:

    • Two TPO 25MM Spacers for 6" RC (OS-TPORC-25MMSP)
    • TPO 50MM Spacer for 6" RC (OS-TPORC-50MMSP)
    • TPO LRS Crayford Focuser for Ritchey-Chretien Telescopes (OS-CF-LRS)
    • TPO 2" to 1.25" Adapter (OS-A2125)

    It can be challenging to figure out which adapters and other accessories you need in order to use your TPO 6-Inch RC visually or photographically. Below you will find several lists that should help make that task a whole lot easier! Links to suggested or required products will be included when applicable so that you can read more about an item and easily add it to your cart. If you have any questions or concerns, feel free to give us a call, start a chat, or send us an email.

     

    Attaching the TPO 6" Ritchey-Chretien to a Mount

     The TPO 6-inch RC comes with a preinstalled Vixen-style dovetail bar which will allow you attach the telescope smaller Bresser, Celestron, iOptron and Vixen telescope mounts. If you mount uses a Losmandy-Style saddle, we recommend using the ADM D Series Dovetail Bar for 6" OTA's.

     

    Using the TPO 6" Ritchey-Chretien Visually

     Below you will find two accessory chains that you can follow if you want to use this telescope visually ending in a 2” or 1.25” diagonal.

     

    Canon EOS, Nikon, Or Sony E-mount DSLR Imaging

    Below you will find the accessory chain that you can follow if you want to use this telescope with a Canon, Nikon, or Sony E-mount APS-C sized DSLRs. Items in the chain that are included as standard accessories are marked as such, otherwise, each piece will be linked to the accessory on our website. Items are listed in the order you would attach them to the telescope.

     

    Imaging With a Dedicated CCD or CMOS Telescope Camera

    Below you will find the accessory chain that you can follow if you want to use this telescope with a dedicated astronomy imaging camera. Items in the chain that are included as standard accessories are marked as such, otherwise, each piece will be linked to the accessory on our website. Items are listed in the order you would attach them to the telescope.

      • With Astro-Physics CCD Focal Reducer for f/9-f/18 Telescopes
        • Two TPO 25MM Spacers for 6" RC (Included)
        • TPO 50MM Spacer for 6" RC (Included)
        • TPO LRS Crayford Focuser for Ritchey-Chretien Telescopes (Included)
        • Astro-Physics CCD Focal Reducer for f/9-f/18 Telescopes
        • The spacers that you will need will depend on several factors, how much you want to reduce the focal length by, how big is your camera sensor, the back focus of your camera, are you using an OAG etc. Generally, we recommend using the TPO M48 Spacers first then use an adapter to reduce down the thread size to get the correct spacing.

      The suggestion above is not the only solution for attaching a dedicated camera. You can a log of accessories in your imaging-train like an adaptive optics unit, field rotator, off-axis guider, or on-axis guider. If you plan on incorporating one of these accessories or still have questions about the adapters you need for your application, we recommend that you contact us. We would be more than happy to help.

      • No Chromatic Aberration
      • Coma-Free
      • Long back focus of 230mm
      • Fixed Primary to eliminate mirror flop
      • Knife Edge Baffling System to improve contrast
      • Two TPO 25MM Spacers for 6" RC (OS-TPORC-25MMSP)
      • TPO 50MM Spacer for 6" RC (OS-TPORC-50MMSP)
      • TPO LRS Crayford Focuser for Ritchey-Chretien Telescopes (OS-CF-LRS)
      • TPO 2" to 1.25" Adapter (OS-A2125)

      Additional Information

      Aperture152 mm (5.98")
      Back Focus235mm
      Camera/Eyepiece Connection2" nosepiece
      Dawes Limit0.76 arcseconds
      Focal Length1370 mm
      Focal Ratiof/9
      Free ShippingYes
      Glass TypeQuartz
      Hightest Magnification304x
      Limiting Magnitude14.7
      ManufacturerTPO
      Optical DesignRitchey Cretien
      Reflectivity96%
      Secondary Obstruction67mm
      Tube Diameter191mm
      Tube Length485mmmm
      Tube Weight12.3 lbs
      Warranty2 Year Warranty

      Customer Reviews

      Based on 1 review Write a review

      Questions & Answers

      Ask a Question
      • Do you stock a second rail for mounting a guide scope?

        We are currently in the process of talking to the manufacture of this telescope about a dovetail plate for the top of the OTA so that accessories can be mounted on the top. For the time being, the best way to get a system that has dovetails on the top &

      • The big central obstruction reduces the contrast in DSO astrophotography?

        Contrast in astrophotography is less important than even illumination and a large, well-corrected field. Unlike in visual astronomy, you can add contrast back in with Photoshop later with astrophotography. It is better to have an obstruction too large tha

      • This OTA delivery 100% illuminated and fixed field in full frame DSLR or only in APS-C?

        Due to a customer pointing out a mistake with the previous answer, I am revising it here. The illuminated image circle is 40mm, however it is not 100% illuminated out to the edge of this field. There is still natural light fall-off that must be correcte

      • What is the capacity of the focuser, in kg?

        The included focuser is fairly lightweight and will carry up to approximately 1.5-2 kg max weight, though we usually do not recommend more than 1.5 kg to prevent flexure of the drawtube.

      • Hello, what is the backfocus of this telescope?

        The official backfocus is 150mm behind the 2" focuser (pulled forward, no 1.25" adapter attached). As the focuser is about 80mm long at minimum, the backfocus from the M90 thread is ~230mm.

      • Given the nature of this specialized scope, of coarse it is intended as an astrograph but how well would the scope function as a visual observation platform? I am new to space photography and visual astronomy with a telescope although I do binocular obser

        Yes! You can use the 6" TPO RC for visual use as well as astrophotography.

      • F/9 is a high number, Is there any focal reducer for this scope?

        Focal ratios of f/8 to f/9 are common with RC telescopes, and even research grade telescopes in the 20-60" range (0.5-1.5 meters) are usually ~f/8. TPO does make a 0.75x focal reducer (f/6.75), but it only works with sensors less than 15mm across the dia

      • What is the weight of the OTA?

        The weight of the 6" f/9 RC OTA is approximately 15 lbs.

      • Does this scope include everything an amateur needs to take pictures, or will I need to purchase anything extra?

        That depends greatly on your definition of "everything", but I would argue that at the least you would need a collimating tool (cheshire or laser with holographic attachment) and potentially a motor for the focuser. For heavier systems, you may need to u

      • Would you know the size of the O-ring in this OTA by the primary mirror. Mine is completely deteriorated. Diameter and thickness?

        We measured the one in the demo 6" TPO RC on our showroom, and it appears to have an inner diameter of ~48mm and a thickness of 3mm.

      • Is this corrected for astigmatism and if not is there a corrector for this model

        Thanks for your question. At this time we are unaware of a corrector for astigmatism for this telescope model.

      • Can you recommend a heavy duty focuser to replace the stock focuser?

        For a manual focuser, the FTF2015 Feathertouch 2" focuser is an excellent option (SI-FTF2015BCR). IF you want a fully computerized focuser, consider the Optec TCFS-i focuser (OP-17668). Both focusers will require adapters to connect to the 90mm thread o

      • Is there a finder scope with a mounting base that will fit the stock mounted finder scope mount or do I need to find a mount to fit other finder scopes?

        The TPO 6" RC uses a standard vixen finder shoe. Any finder that has a standard vixen finder base will be compatible with this telescope. Give us a call or email us and we will match the finder that best fits your needs.

      • There is another site that offers a 6" F9 RC scope that seems to have more or less identical specs to yours, except that it claims a maximum 300x power, while yours specs a maximum 180x power. Can you explain the discrepancy, please?

        Our website also has 300x magnification for the TPO 6" f/9 RC Astrograph.