Tele Vue 1.25" 3x Barlow Lens

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 Anyone telling you otherwise is using outdated information.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