Editor’s note: The Takahashi FSQ-106N has been superseded by a new version, the FSQ-106EDX4.
Takahashi is one of those brands that is spoken of with a sense of awe. Anyone who owns a Takahashi telescope must be a serious imager! The Japanese telescope maker started as a sand-casting business in 1932 and began building telescopes in 1967. They are now widely known for their premium telescopes. But do they live up to the hype?
I became a proud owner of a Takahashi FSQ-106N at the 2019 Texas Star Party. I bought it from my uncle after he upgraded to a newer version. The scope is heavy, weighing in at 13 lbs (6 kg) – the same as my 8-inch Schmidt-Cassegrain!
Unfortunately, the 106N version is no longer available; it has been replaced by the more-expensive FSQ-106EDX4, which uses ED (extra-low dispersion) glass instead of fluorite and uses a better design for the camera rotator and focuser. But with the 106N as great as it is, the 106EDX4 is surely even better, promising superior contrast and color correction compared to the earlier models.
The weight of the 106N results from having four pieces of glass, since this apochromatic refractor is a quadruplet. The optics are a modified Petzval design with one fluorite element at the objective, and the second at the opposite end of the scope, inside the focuser.
With the focuser and dew shield retracted, it is only 20.5 inches (52 cm) long, with a focal length of 530mm and aperture of 106mm, making the FSQ-106N an f/5 instrument that is airline-portable. At its weight, size, and focal length, it works very well even on lower-end equatorial mounts; I have used it on both my Celestron Advanced VX and iOptron CEM40 with great results.
On the rear of the telescope is a manual 360° rotator, and the four-inch rack-and-pinion focuser is easy to attach to an electronic focuser (the ZWO EAF is pictured above). Takahashi also sells an extender and a reducer to change the telescope to either an 850mm f/8 or a 318mm f/3 instrument (for a price!).
The FSQ-106N has an astounding 88mm image circle, allowing it to accommodate even the largest camera sensors available to amateurs. The quadruplet design and built-in field flattener promise little coma and chromatic aberration, and I am happy to report that they deliver on that promise, at least with the 4/3 sensor on my ZWO ASI 294MC Pro and 1600MM Pro cameras.
Zooming into the upper right corner of a single raw subframe (300s) reveals a small amount of coma and chromatic aberration. Overall, the stars are well-shaped and pinpoint.
One problem that all Takahashi refractors seem to suffer is sensitivity to temperature for focusing. Even a one- or two-degree Fahrenheit or Celsius change in temperature can noticeably de-focus the image; I have my electronic focuser set to re-focus every one degree of temperature change, which takes away from imaging time.
My experience with the Takahashi FSQ-106N can be summed up with “Believe the hype!” Its clarity, contrast, and low coma and chromatic aberration blows the other refractors I have used out of the water. Of course, that kind of performance comes at a price, but if you are seeking high-quality imaging in a portable package, I cannot recommend the FSQ-106N highly enough.
MSRP: $6200 for the current model, the FSQ-106EDX4