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.
The 2.5X Powermate Barlow is a 4-element parfocal, compact amplifying lens system. POWERMATE consists of a negative achromatic doublet plus a positive "pupil-correcting" doublet. While it looks and functions like a Barlow, your eyepiece will operate with pupil locations where the designer intended, avoiding mismatch problems. POEWRMATE optimally mates its power to your eyepieces. No additional "interface lens" is needed, since POWERMATES have it built-in.
In addition to full multi-coating, POWERMATE includes other Tele Vue special touches such as a safety undercut on the chrome barrell, and captive lock screws that can't fall out. Tele Vue's 100% QC program at f/4 insures that POWERMATE will add dramatic power (and NOTHING ELSE) to your favorite eyepieces. If, for example, you own a 22mm Panoptic, you'll have the power of an 8.8mm focal length eyepiece with the 2.5x POWERMATE. The POWERMATES are constructed to be parfocal with Tele Vue's 1-1/4" 90 degree diagonal (often used in Ranger telescopes) adding convenience not previously available with any Barlow. The 2.5X POWERMATE has no filter threads
Dobsonian/Newtonian owners usin g Tele Vue's Paracorr coma corrector should place the 2.5x or 5x POWERMATE (or Tele Vue 2x or 3x 1-1/4" Barlows) into the Paracorr's 1-1/4" adapter (i.e., between the Paracorr and the eyepiece). For 4x POWERMATE (or Tele Vue 2x Big Barlow), first insert the 4x POWERMATE into the focuser, then the Paracorr into the 4x POWERMATE.
This Version accepts the Tele Vue PTR-1250 T-ring Adapter for close coupling cameras and CCD Imagers.
For imaging , the user simply unscrews the eyepiece holder barrel and screws on the T-Ring Adapter instead
Reviewed by 3 customers
This is a quality 'magnificator' for your 1.25" EP. As advertised, it is better than a normal barlow and provides 2.5X magnification and nothing else. Yes it does make you get some more money out of your pocket than barlows, but it does a better job so I think it's worth it.
Use this with my 85mm and 105mm refractors and it works great!! To my eyes, it is shows a much clearer visual image than the barlow I was previously using. Another wonderful product from Al & David Nagler and the folks at Tele Vue!!
Although I have only used the Tele Vue 2.5 Powermate on selected viewing occasions at our LCAS Astronomy Club dark sky sites,I found it to be a wonderful addition to my deep sky viewing capabilities. The clarity and eye relief the powermate offers adds to a great pleasure in the astronomy hobby.