About the TeleVue 2X Barlow - 1.25"... Properly designed Barlow lenses do wonderful things: They amplify power, slow the telescope''s f/# (improving eyepiece sharpness), and give designers the opportunity to compensate for telescope eyepiece aberrations. Tele Vue Barlow Lenses use multi-coated high index glasses for optimum aberration correction, exceptional contrast with virtually no light loss. Observed performance is aberration free, even when tested with f/4 telescope. TeleVue Barlow Lenses even improve our competitor''s telescope eyepieces and telescopes! "I originally designed the TeleVue Barlow Lens line to complement the high performance of our TeleVue Telescope 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 lens will not degrade your telescope''s optics. Anyone telling you otherwise is using outdated information. Moreover, the highly regarded Nagler TeleVue Telescope 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 Be sure to check out our line of TeleVue Telescopes, TeleVue Telescope Mounts and TeleVue Telescope Accessories. Don''t forget TeleVue Telescope Eyepieces, TeleVue Dioptrx and TeleVue Eyepiece Filters, too! TeleVue 2X Barlow - 1.25" Features... Product design and execution deliver consummate satisfaction Features include parfocal-ization, 1.25" filter threads, captive lock screws that won''t fall out and full multicoatings All Tele Vue Barlows now use brass clamp rings for secure, non marring holding of eyepieces and accessories Multi-coated high index glasses for optimum aberration correction, exceptional contrast with virtually no light loss Every Tele Vue Barlow must pass the same rigorous f/4, full field testing as all their eyepieces TeleVue 2X Barlow - 1.25" Specifications... Optics Type: 2X Barlow Lens Barrel Size: 1.25" Coatings: Full multi-coatings Weight: 0.3 lbs. Parfocal: Yes Threaded: Yes Glass Type: High Index Warranty: Limited Lifetime TeleVue Product Number: BLW-2125
