Tele Vue NP127is Refractor

Description Televue was determined to make the NP series optically, mechanically, and functionally as perfect as possible for imaging up to 50mm diagonal chips without penalty to its near ideal visual operation. How? By applying the developments created for the Tele Vue-60is to the new NP101is and NP127is and then going beyond. The NP101 (540mm, f/5.4, 4") and NP127 (660mm, f/5.2, 5") maintain their optical specifications yet with redesigned 4-element optical systems. Larger rear lens groups absolutely minimize vignetting in formats up to 50mm diagonal. For these large chips an optional field corrector was developed so the corners of the newly brightened edges would virtually be as perfect as the center of the field. Next, to take full advantage of the larger lenses, they developed a larger focuser and draw tube having a 3" front aperture and 2.4" rear aperture. This eliminates any restriction of the larger diameter converging light cone. Tele Vue build and test the rack and pinion f