VIXEN FLUORITE 102mm OTA: sharper than a Tak!

This is Vixen’s largest, newest fluorite APO refractor, the FL102S. It is indeed sharper than a friend’s Takahashi FS102 in side by side tests. It gives superior star tests; out of focus diffraction rings are very similar on both sides of focus. At f/9, it also has a slight advantage in eliminating residual chromatic aberration and spherochromatism, the two major sources of “color error” in premium apochromatic lenses. In this respect, fluorites are noticeably superior to ED glass. This telescope also gives excellent results in the Ronchi test: very straight lines (10 line/mm grating).

This scope is only about a year old and looks like new. The glass is perfect, it has not even needed a dust-off. The focuser works very smoothly. The lens cap, 2” - 1.25” reducer, tube rings, and 6x30 finder with dovetail bracket are included. This OTA weighs less than 9 lbs. (4 kg); it’s lighter that other premium 4” APOs.

Experienced Vixen users know that their refractors have long been something of a bargain. They lavish considerable attention on finishing the optics to a high standard, even on their achromats. Their fluorites get even more attention. This example is the equal or better of any fluorite I have ever used in terms of fine optical figure. It stands out even among Vixen fluorites.

The discounters sell new OTAs for $2365. That’s a bargain if you demand the best possible images that a 4” can deliver. I need to pay for more aperture. The mount shown in the photos is not included. It is offered separately in another ad: #362997.

My price is $1750 + shipping.