The Tele Vue 3 Inch BIG Paracorr Type 2lets you go even bigger than the 2-inch Paracorr 2. Now with an extended 80 mm back focus and it fits a 52 mm diagonal.
The new wave of faster parabolic mirrors has given rise to the growth of ever larger aperture Dobsonian mounted Newtonians for the amateur astronomer. These large and fast instruments have the distinct benefits of delivering greater true fields and can eliminate climbing ladders. However, their performance was severely limited by the extreme coma produced as a natural consequence of the primary mirror's shape. With the successful development of our Paracorr Type 2, for full-field correction of parabolic mirrors as fast as f/3 (coma is reduced to the equivalent of an f/20 mirror) we've dramatically improved the optical performance and practicality of large aperture Newtonian/Dobsonian telescopes.
Imagers have started taking notice of the great price vs. aperture value of these fast, large aperture instruments especially when combined with large chip CCD cameras. However, while the 2-inch Paracorr Type 2 was the answer for coma correction, its 2-inch format limited available light (vignetting) with increasing field angle. The 2 format is fine visually since secondary mirror size limits maximum exit pupil diameter to around 7 mm. The widest true field eyepiece choice with an f/3 (f/3.45 when used with Paracorr) is, therefore, Tele Vue's own 21 mm Ethos which delivers a 6.1 mm exit pupil at f/3.45.
The 3-Inch Big Paracorr, designed by Paul Dellechiaie of Tele Vue, was created to extend the Paracorr type 2-inch's optical benefits for imaging applications by amateurs and professionals using CCD formats as large as 52 mm diagonal. Back focal length has been extended to 80 mm to allow for additional accessories to be placed in the optical path. The 5.1-inch length optical assembly is topped with a stop flange having 3.40 to 24 pitch threads to handle various equipment applications.
OPT Product Number: TE-VIP-3010