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Takahashi - Sky-90II 3.5" f/5.6 Fluorite APO Refractor Optical Tube Assembly - DISCONTINUED


Discontinued Product

Manufactured by: Takahashi


This is a discontinued item. We recommend the Explore Scientific ED80mm f/6 Air-Spaced Triplet Refractor as a replacement.

Takahashi Sky 90II Fluorite APO Refractor OTA

  • Takahashi Sky 90II is a refractor telescope 90mm (3.5") f/5.56 flourite doublet apochromatic optical system.
  • Takahashi Sky 90II has a focal ratio of f/8.9 for flat field lunar and planetary photography.
  • Takahashi Sky 90II has a limiting visual magnitude of 11.5 and a 1.3 arc seconds of resolution.
  • Full 5 Year Manufacturer Warranty.
  • Ships Direct From Takahashi America In Texas.


Important: Takahashi America requires the shipment of all Takahashi Telescopes to be done via 2-Day Air or Faster for the Takahashi 5 Year Warranty to be valid. Select UPS 2 Day Air or faster when ordering this telescope. If something other then 2-Day Air shipping is selected our customer service team will contact you to make the change.

The Takahashi Sky 90 is a refractor telescope that executes optical excellence. Containing calcium fluorite crystal lens that are created in a laboratory environment and are vacuumed hard coated for maximum light transmission, this refractor scope delivers absolute precision. The crystal lens is combined with low dispersion glass to offer optical quality that exceeds any other extra-low dispersion glass refractor on the market today. Because of the controlled environment in the production of the fluorite crystal creation, absolute precision is created and reveals Takahashi's true apochromatic optical systems that have virtually perfect color correction.

Takahashi stops at a two element air spaced design which in turn eliminates an extra light robbing lens and virtually stops any possibility of oil spacing becoming corrupt with age. Lens collimation can be adjusted to allow for precision tunning. To do this simply apply an optional Cheshire eyepiece and adjust the twelve locking collimating screws located on the primary lens cell assembly. The construction of the Sky 90 was made with portability in mind. It is constructed from lightweight, durable, powder-coated aluminum. The outer diameter of the Sky 90 is 95mm and there is a generous 2.5" rack and pinion focuser included with compression fitting 1.25" adapter and 2" adapter with thumbscrews. The 2.5" focuser is of high quality and offers smooth performance. The focuser also has the capability of supporting heavy accessories with ease.

Portability is one of the best attributes in the construction on the Sky 90. Having a built-in lens shade retracted and focuser fully in, the Sky 90 measures only 13.8", weighs only 7 pounds, and comes equipped with a hard carry case. The latest Takahashi Sky 90 II NSV telescope model is an all and one package delivering outstanding quality through its fluorite doublet apochromatic optical system and is a true portable design making it convenient for users to observe on the go. The Sky 90 is well suited for astronomy but can also be a great asset for birding. The Sky 90 accepts the FS series photographic adapters and can also work with optional 5 element Extender-Q which will increase the focal ratio to f/8.9 for flat field lunar and planetary photography. There is also a mounting block on the focuser cell provided for the optional finderscope and bracket.

This 500mm focal length telescope will offer up to 178x of practical magnification with a limiting visual magnitude of 11.5 and a sweet 1.3 arc seconds of resolution which will fulfill all your refractor needs. When it comes time to optical perfection, look no further then the Takahashi Sky 90 II NSV.


Additional Information

Name Takahashi - Sky-90II 3.5" f/5.6 Fluorite APO Refractor Optical Tube Assembly - DISCONTINUED
Manufacturer Takahashi
Model TSK9001
Discountinued Yes
Custom Stock Status Out of Stock
Backfocus Distance 170.50mm
Focal Tube Travel 63mm