Used Takahashi FSQ 106N - Petzval Quadruplet Apo f/5 Refractor and Field Flattener/Barlow (EXQ-1.6X)

  • Sale
  • $4,400.00
  • Regular price $6,900.00

Free Standard Shipping Available (CONUS Only)

Contact use for ordering information.

This is a used Takahashi FSQ 106N.  This model is in used but very good condition, with clean optics.  This item includes the 1.6x Extender, which is a combination Barlow and field flattener, which is described at the end.  Also included are tube rings attached to a Losmandy dovetail.  

Includes small Takahashi soft case. 

Full reviews of this model can be found here as well as here.  


This older model FSQ has since been superseded by the more-expensive FSQ-106EDX4, which uses ED (extra-low dispersion) glass instead of fluorite and an improved design for the camera rotator and focuser.  However, all the Tak quality you've come to expect and enjoy is present on this model.  The specs for the similar, but different, EDX4 are below:  

The Takahashi FSQ-106EDX4 is a redesign of the popular FSQ-106 and is a superior flat-field super quadruplet refractor.  This redesigned version features a flat field advanced Petzval quadruplet design, with extra-low dispersion (ED) glass for super color correction in the UV, visible and IR wavelengths.  This optical design results in pin point star images and increased field illumination.  Designed from the ground up for digital imaging, this new 4 element / 4 group design is also capable of stunning visual performance.

Some of the features of this outstanding design include:

  • Completely new optics for digital imaging, featuring two premium ED elements for outstanding color correction (NOT ON THIS 106N model)
  • An advanced Petzval design includes an almost full aperture G3 lens to ensure greater image illumination
  • A flat field without the need for an additional flattener, across a large 88 mm image circle
  • Generous 178 mm back focus allows the user to attach a variety of imaging cameras and accessories, 2 inch diagonals, and many other visual devices including bino viewers.
  • A 4 inch, heavy duty focuser with a an included camera angle adjuster for precise rotation of CCD cameras
  • An anti-torquing draw tube that uses a second rack located on the top of the tube and loaded with ball bearings to prevent any rotation when a heavy instrument package is attached.
  • Airline portable, with a total length of less than 17 inches with the lens shade retracted

Please note: mount, tripod, tube holder and finder sold separately.

Takahashi FSQ-106EDX4 Specifications

  • Model: FSQ-106EDX4
  • Part Number: TQE10630
  • Optical Type: Fluorite ED Quadruplet
  • Aperture: 106mm
  • Resolution: 1.09”
  • Limiting Magnitude: 11.9
  • Light Gathering Power: 229X
  • Focal Length: 530 mm
  • Focal Ratio: f/5
  • Image Circle Diameter: 88 mm
  • Tube Diameter: 125 mm
  • Tube Length - Extended: 675 mm
  • Tube Length - Retracted: 580 mm
  • Tube Weight: 7.0 kg/15.43 lb.

Extender: Takahashi Extender Q 1.6X - 2”
  • Product Number: TKA36595
  • Effective Focal Length: 850 mm
  • Effective Focal Ratio: f/8
  • Resulting Image Circle: 44 mm

Takahashi 1.6X Extender-Q for Takahashi refractors - EXQ-1.6X

This dual purpose Takahashi optical system is both a 2" 1.6x Barlow and a field flattening photographic tele-extender designed for use with Takahashi FSQ-106/Sky 90 refractors.  

The 1.25" Extender-Q is a visual and photographic amplification device designed for use with older Takahashi FSQ-106N and Sky 90 refractors. It changes the FSQ-106N from a 530mm f/5 to an 850mm f/8 and provides a 44mm image circle with a 3° field. The Sky 90 changes from a 500mm f/5.6 to an 800mm f/9. However, tests have shown that the Extender-Q will give you similar 1.6x magnification and focal ratio results with every Takahashi refractor, and not just the fast focal ratio FSQ-106 and Sky 90.

The Extender-Q threads into the Takahashi focuser drawtube before the 1.25" eyepiece adapter and so cannot be used with non-Takahashi scopes.

This extender is not a simple two-lens achromatic Barlow lens, but rather a sophisticated optical amplification device using five lenses in three groups that functions as both a visual Barlow and a photographic tele-extender. Its five-element optical system is fully multicoated for maximum light transmission and contrast. The Extender-Q produces a flat, color free, extremely high contrast image that can be used for high magnification lunar and planetary visual observation or photography and CCD imaging.

An additional advantage of the Extender-Q is that it corrects the image in the ultraviolet portion of the spectrum that is invisible to the eye, but is easily recorded by CCD cameras. Stars that radiate strongly in the ultraviolet appear closer to their naked-eye visual appearance when imaged on a CCD camera through the Extender-Q. They do not have a bloated appearance on photos due to their normally invisible UV component being recorded by the CCD camera and added to the visual image. This feature only adds to the photo/visual capabilities of Takahashi scopes.

The Extender-Q threads into the focuser drawtube, in place of the 1.25" eyepiece adapter (which is unthreaded from the focuser drawtube and reinstalled on the end of the Extender-Q). Several extension tubes in the Extender-Q body add the needed extra light path distance to allow eyepieces and a 1.25" star diagonal to focus. An optional 2" adapter #TEQ0002, shown below, threads into the end of the Extender-Q in place of the 1.25" adapter to let you use a 2" star diagonal and 2" eyepieces with the Extender-Q.

The maximum length of the Extender-Q (5.5") is only used for photography and straight-through visual observing. With a star diagonal, two of the extender tubes in the Extender-Q body are removed, shortening the Extender-Q length to 3". Rubber grip rings on each section make it easy to assemble and disassemble the unit.

    SKU: U2202-MD-TAKFSQ106N