About the TeleVue NP-127is APO - Imaging System Refractor Telescope...
For 25 years, TeleVue Telescope has pushed the boundaries of APO refractors, as well as TeleVue Telescope Eyepieces, to the recognized pinnacle of performance. We were gratified but not surprised that Backyard Astronomer'''s Guide said of the NP101: "Optics don'''t get any better than this." No wonder Sky and Telescope rated the NP tops (May & June 2002) and selected it as the test instrument for its landmark review of the SBIG STL-11000 CCD camera (July 2004). The "is" versions of the Televue-60, 102i, NP101 and Televue NP127is APO retain the exemplary wide field and planetary visual capability while adding new TeleVue Telescope features to make imaging easier and more flexible.
Just what makes the TeleVue NP-127is APO - Imaging System Refractor Telescope so special? The standard by which it is built. The four-element air-spaced Nagler-Petzval TeleVue Telescope system begins with a precision machined 660mm focal length optical tube that'''s fully internally blackened to prevent any stray light inflections. Then it'''s combined with a 127mm aperture extra low dispersion glass doublet as the primary lens with a with a secondary field-flattening/aberration-correcting extra low dispersion glass doublet at the opposite end. All TeleVue Telescope optical surfaces receive index matched multi-coatings. This design offers up diffraction-limited apochromatic peformance - simultaneously correcting for field curvature, astigmatism, spherical aberration, coma, secondary spectrum and spherochromatism. Combine with a TeleVue Mount for excellence in astrophotography.
TeleVue Telescope was determined to make the TeleVue NP-127is APO - Imaging System Refractor Telescope 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 Televue-60is to the new NP101is and NP127is and then going beyond. The NP101 (f/5.4, 4") and NP127 (660mm, f/5.2, 5") maintain their optical specifications yet with redesigned 4-element TeleVue Telescope optical systems. Larger rear lens groups absolutely minimize vignetting in formats up to 52mm 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.
Don'''t forget, we carry plenty of TeleVue Accessories, too! Look for TeleVue Telescope Eyepieces and TeleVue Telescope Filters for visual observers - as well as TeleVue Finderscopes and TeleVue Dioptrx!
TeleVue NP-127is APO - Imaging System Refractor Telescope Features...
- New lens prescription delivers smaller spot sizes over a broader wavelength range
- Both the optical and mechanical designs have been revised to further reduce atmospheric defocusing ability
- Handsome new shapes of the dew shield and rear cell bring a refined elegance to this high performance APO refractor
- Fast f/5.2, flat-field optics and the ability to image across a 52mm diagonal sensor
- Focuser tested to hold and drive a minimum of 6 lbs of weight in vertical orientation
- Fully internally blackened to prevent any stray light inflection
- Offers up diffraction-limited apochromatic peformance - simultaneously correcting for field curvature, astigmatism, spherical aberration, coma, secondary spectrum and spherochromatism
- New 10:1 focuser pinion assembly, made for Tele Vue by Starlight Instruments
- Package Includes: Enlarged focuser with 3" entrance aperture and 2.4" exit aperture, Focuser body has brass clamp ring with 2-lock knobs, Accessory end-ring with tilt capability and 4-lock knobs, Imaging insert threaded for Imaging System components, 2" accessory insert for visual or other 2" accessories, Focusmate dual-speed focuser 10:1, Sliding metal dew shield, Screw-on metal lens cover and Hard-shell carry case
TeleVue NP-127is APO - Imaging System Refractor Telescope Specificatons...
Type: APO (Nagler-Petzval) Refractor
Objective (mm): 127
Focal Length (mm): 660
Focal Ratio (f/#): 5.2
Drawtube/Focuser: 2.4-inch, Focusmate dual-speed rack/pinion
Length OTA (inch): 33.5
Length with diagonal (inch): 36.5 (with 2-inch diagonal)
Weight OTA/Std. Config (lbs): 15.4 / 18.3
Maximum Visual Field (deg.): 4 (with 2-inch 55mm Plossl)
Maximum Recommended Power (x): 300TeleVue Product Number: NPI-5054