Televue NP 101 APO

Nagler's latest entry in the premium-refractor market is the NP 101. Like some previous Tele Vue refractors, the NP 101 is a four-element design with a full-aperture doublet objective up front and subaperture doublet near the back. . . . While a field flattener is an add-on accessory with some apos, with the NP 101 a flat field is an integral part of the design, and the scope delivers pinpoint star images across wide-field eyepiece views and on 35-mm film. . . . As I discovered at first glance through its optics, the NP 101 improves upon the now-discontinued Tele Vue-101 and Genesis models by completely eliminating chromatic aberration. And it achieves this ultimate level of apochromatic performance in a tube about 6 inches shorter than those earlier models.

Fitted with Tele Vue's remarkable 31-mm Nagler eyepiece, the NP 101 showed pinpoint stars across a vast 4½° field. . . . This is a great combination for panoramic 'rich-field' views of the Milky Way.

Great optics are easy to evaluate — the NP 101 showed no sign of any aberrations, period. End of review! But to elaborate -- under a star test at high power I saw no color, no astigmatism, no spherical aberration, not even any asymmetry in extrafocal patterns from sphero-chromatism. Bright stars appeared as clean, white disks right through focus, with no magenta or cyan fringing inside or outside of focus. In focus, stars appeared as tight, sharp Airy disks, surrounded by a subtle inner diffraction ring and no spurious fuzz — a textbook-perfect pattern.

Saturn appeared etched into a dark sky. Differences in ring shading were obvious, as were several of the planet's faint moons. Jupiter's disk looked clean white with no discoloration from unfocused wavelengths or filtering effect of glass or coatings. Here was pure unadulterated light, just what an apo refractor should deliver.

The tube's internal blackening worked well. Low-power views showed no sign of flares or ghost images from bright objects just outside the field. This is clearly one of the world's best telescopes, able to match or exceed the performance of any other premium apo of this aperture.

Tele Vue NP 101 is a no-compromise design that performs well for all visual and photographic purposes. It can cruise effortlessly from superwide-angle scenes to high-resolution planetary views. Although it carries a premium price, the NP 101 may be all the telescope many observers ever want.

Gibraltar Mount Head and Ash Tripod: An incredibly rigid and portable 17 lb. (7.7kg), simple to use mount that cradles a telescope at its center of gravity for ideal balance at any viewing position

The mount head is made of fully machined of aluminum which is black anodized, with brass elevation bearings and azimuth nylon bearing providing smooth vertical travel from 10 degrees below the horizon up to 85 degrees overhead, and smooth full 360 degree rotation. Clutches on the elevation axis permits the operate to compensate for changing accessory loads, or with the Azimuth control to lock the telescope in place. The tripod is made of American ash, in a two section extension design providing a range of 3 feet up to 5 feet, with accessory tray/leg brace. The "Gibraltar" mount solved a problem of ease of use for those who are frustrated by the weight and relative complexity of equatorial mounts, and it provides a mount far better suited to terrestrial applications than an equatorial mount or common camera tripod would be. These mounts remain available with either a beautiful ash tripod in natural finish (Yes, ash is the hard wood used to make baseball bats) with black trim, or a in walnut finish. Since it's introduction the "Gibraltar" head has been engineered to accept optional encoders to feed a "Digital Setting Circle" CPU such as that offered by TeleVue and third party units; this helps one to navigate the sky and find objects that might be hard to find particularly from suburban settings.

"Starbeam" Sight: Beautifully machined and black anodized aluminum, on a quick release machined hardware. Battery powered illuminator is adjustable in brightness; it projects a 10 arc minute diameter red dot onto a transparent 40mm clear aperture window so that the dot appears to be over wherever the scope is pointed. Easy to view straight through or at right angles, with six arc minute accuracy the Starbeam makes "star hopping" easy.

• Aperture: 101mm (4 inches) 
   
• Focal Length: 540mm (f/5.4) 
   
• Optical Design: 4-element, 2-group Nagler-Petzval apochromatic (APO) refractor 
   
• Flat-Field Performance: Designed for a flat, distortion-free image, ideal for photography. 
   
• Mechanical Features:
  • Sliding metal dew shield for improved contrast and dew prevention. 
     
  • Brass clamp ring and tension screws on the focuser for stability. 
     
• Portability: Compact and lightweight for travel, often able to be carried in carry-on baggage. 
   
• Included Accessories: Hard-shell carry case, metal lens cover.