Takahashi FSQ-85EDX OTA

Takahashi FSQ-85EDX OTA

With the success of short refractors and improvement of the performances of CCD and DSLR cameras, Takahashi introduces the FSQ-85ED, more itinerant than the FSQ-106ED model, and intended for deep-sky and wide field photographers.

The FSQ-85ED is based on the same ED glass Petzval quadruplet design as the FSQ-106ED model, but offering a focal length of 450mm and a photo field of 5.6°, which is ideal for photography. It is equipped with an oversized rack-and-pinion focuser and an independent camera angle adapter. An optional focal reducer is also available in order to transform the refractor into a true astronomical tele objective with a focal length of 328mm and with a focal ratio of 3.9, providing a field of view of 7° and a 40mm image circle.

Weighting only 4kg without accessories, you will not need a heavy mount. It becomes easy to take pictures of the deep-sky while transporting your telescope under the best skies.


The FSQ-85ED modified Petzval quadruplet design is the same as the FSQ-106ED one. It has a built-in flattener inside the optical tube, offering a field of 5.6°, essential for taking quality pictures. It is thus not necessary to add any other optional accessory. With a focal length of 450mm, the image circle is 44mm width. The addition of a 0.73x focal reducer makes it possible to change the focal ratio from 450mm (F/5.3) into 328mm (F/3.9). It then becomes a true teleobjective for the deep sky.

The FSQ-85ED is equipped with an oversized rack-and-pinion focuser, just like the 106ED. However, the camera angle adjuster has been taking apart from the focuser to come back to a more traditional position where accessories are screwed on focuser tube.
The rack-and-pinion has been oversized on purpose to gain in precision and effectiveness. This focuser is a model of precision. It is driven by two focus wheels with a 1/7 micro-focuser.

Although its design resolutely directs it towards astrophotography, the FSQ-85ED can be equipped with various accessories including those for observation. Please go to the system-charts section to see the different possible options. With a 220mm back focus, no matter which accessory you will pick up, you will have different choices of uses and assemblies.
The FSQ-85ED has a specific focal reducer (see the Accessories section) that deep-sky astrophotographers, wishing to have a very large field, will enjoy.

Optical Specification:

  • Optical design- Modified Petzval quadruplet apochromat
  • Aperture- 85mm
  • Focal length- 450mm
  • Focal ratio- F/D 5.3
  • Resolution- 1.5”
  • Limiting magnitude- 11.6
  • Light grasp- 178x
  • Image circle- 44mm
  • Photo field- 5.6°
  • Back focus- 197.5mm
  • Focal length (With Reducer-QE 0.73x)- 328mm
  • Focal ratio- F/D 3.86
  • Image circle- 40mm
  • Photo field- 7°
  • Metal back- 72.2mm
  • Tube length (min/max) w/ standard accessories- 553mm-645mm (retracted dew shield/extended dew shield)
  • Tube diameter- 95mm
  • Rack-and-pinion tube diameter- 80mm
  • Tube weight- 4Kg