The Tele Vue 3x Barlow provides triple the magnification when used with any 1.25" eyepiece in your collection. For less magnification check out the Tele Vue 2x Barlow.
The chart below shows the effective magnification when spacing is introduced between the Barlow lens and image plane of your camera or eyepiece
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 light loss. Observed performance is aberration free, even when tested with f/4 scopes. They even improve our competitor's eyepieces and telescopes!
Compromise image quality in any part of the optical chain and you've compromised every part! Tele Vue product design and execution deliver consummate satisfaction. Every Tele Vue Barlow must pass the same rigorous f/4, full field testing as all our eyepieces.
All Tele Vue Barlows now use brass clamp rings for secure, non marring holding of eyepieces and accessories.
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.