Tele Vue 3x 1.25″ Barlow Offered in 2x and 3x magnifications, these 1¼” Barlows perform identically. Simply choose either or both based on your eyepiece collection. Features include parfocal-ization, 1¼” filter threads, captive lock screws that won’t fall out and full multicoatings. Barlows Concept: I originally designed the Tele Vue Barlow line to complement the high performance of our eyepieces. Only 2 elements of high index glass were required to reduce all aberrations to well below the airy disc in an f/4 system. It has taken a good 15 years, but I think we’re finally laying to rest the popular myth of the “degrading Barlow.” In a 1997 Sky & Telescope review, Terrence Dickenson wrote “…Technology has erased the old objections. A modern Barlow will not degrade your telescope’s optics. Anyone telling you otherwise is using outdated information. Moreover, the highly regarded Nagler eyepieces and their clones have built-in Barlows – ample evidence that the lens is not some detrimental intruder.” Thanks Terry, I couldn’t agree more. Al Nagler Properly designed Barlows do wonderful things: They amplify power, slow the telescope’s f/# (improving eyepiece sharpness), and give designers the opportunity to compensate for eyepiece aberrations. Tele Vue Barlows use multi-coated high index glasses for optimum aberration correction, exceptional contrast with virtually no lightloss. Observed performance is aberration free, even

Tele Vue Barlows: “An Optically Perfect Window” Properly designed Barlows do wonderful things. First, they amplify power while retaining the eyepiece’s eye-relief. Second, they slow the telescope’s f/#, which improves eyepiece sharpness. Third, the designer can introduce compensations for eyepiece aberrations. Tele Vue’s 1 1/4″ 2x and 3x Barlows were envisioned as magnification windows. Multi-coated high index glasses assure optimum aberration correction, exceptional contrast and virtually no light loss. Tele Vue Barlows achieve their design goals even when tested by the fastest scopes. The Tele Vue design approach includes mechanical conveniences. The Barlows are parfocal with Tele Vue eyepieces. The 2X Barlow is threaded for 1 1/4″ filters.