As TeleVue's reputation has established it as the epitome of quality excellence, the company has not been satisfied to rest on its laurels, but rather to push the envelope in innovation and technology. A perfect example is evident in the new "is" version of the 127mm f/5.2 Nagler-Petzval APO Refractor. Both the optical and mechanical designs have been revised to reduce atmospheric defocusing sensitivity (visually the difference is virtually indiscernible). The new lens prescription delivers smaller spot sizes over a broader wavelength range than previously, while a new stainless steel front cell helps provide better thermal stability in extreme climates. Advanced multi-coatings are applied to maximize contrast and transmission. Still the fastest in the industry, there is just no competitive comparison considering its f/5.2 speed and flat-field.
The instrument has also been mechanically updated from its longer captive dew shield to its new 10:1 focuser pinion assembly, made for Tele Vue by Starlight Instruments. Along with an all new gloss black anodized metalwork treatment, the handsome new shapes of the dew shield and rear cell bring a refined elegance to this high performance APO refractor.
The non-vignetting focuser retains its 3” input and 2.4” output to reduce bulk and permits imaging across the largest commercially available CCD chips (52mm diagonal). No need for a heavier, more cumbersome 3” focuser. Every 2.4” focuser we make is tested to hold and drive a minimum of 6 lbs of weight in vertical orientation.
CCD cameras have challenged telescope optics beyond anything ever placed at the focal plane. I knew our APO objectives were up to the challenge, and with the proper tweaks would be extraordinary tools for the imager. With Tele Vue Imaging System telescopes, we have refined our instruments and optional equipment beyond anything a CCD chip has seen. We started small (literally) in 2005 with the Tele Vue-60is and available Digital Micrometer Kit. Achieving critical acclaim with the 60is, we were encouraged to further develop "is" telescopes and accessories to maximize aperture, real field coverage and performance, and to make the processes easier for the imager. - Al Nagler
For 25 years, Tele Vue has pushed the boundaries of APO refractors, as well as 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 NP101 tops (May & June 2002) and selected it as the test instrument for its landmark review of the SBIG STL11000 CCD camera (July 2004). The "is" versions of the Tele Vue- 60, 102i, NP101 and NP127 retain the exemplary wide field and planetary visual capability while adding new features to make imaging easier and more flexible.
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 NP127 (660mm focal length, f/5.2,) maintains the original 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.
In order to take full advantage of larger lenses, a non-vignetting focuser was developed to prevent any restriction of the larger converging light cone. The draw tube has a 3" front aperture and 2.4" rear aperture. This new draw tube also permits quick change from visual to imaging operation and allows full camera rotation without focus change. In addition, it has the capability to correct for any residual focal plane tilt and accepts a "position stop" for a digital micrometer to allow repeatable focus measurement to 0.0001".
To maintain squareness to the optical axis while changing camera orientation, the draw tube has four lock screws that tighten against a taper on the "imaging insert" ring. This insert is threaded to accept Tele Vue's new Imaging System accessories including large diameter extension tubes, optical accessories, and camera and CCD attachments, all with mating threads.
The Focusmate 6:1 planetary ball type reduction focuser provides extremely sensitive focus adjustment, measurable with the optional Digital Micrometer Kit to better than 1/10,000". Also, the optional Focusmate Driver permits electronic motor control of the focusing process. The Focusmate Driver has direction push-buttons and adjustable speed. A tap on the button permits vibration-free focusing in steps as small as approximately 0.0005". The Focusmate Driver can be remotely computer controlled with Focusmaster Computer Interface.
TeleVue has been known for producing visual instruments "even better than you imagined." TeleVue aims to achieve the same with their imaging equipment. Dedicated local machinists and in-house staff are as committed as ever to deliver on these quality and performance goals.
Focusmate™ is provided as standard equipment with the NP127is and is the first component of a comprehensive focus solution devised by TeleVue that includes choices for local and remote display of focus position, local and remote control of focus, and integration with TeleVue's own digital encoders and software for display locally or remotely of position. This begins with digital focus position readout by either 10 Micron Resolution kit or 1 Micron Resolution kit. And your choices continue with the Focusmaster™ module and choice of TVFocus, or TVFocusPlus, or third party computer software. No other telescope maker provides their customer with so many choices!
- 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
- Hard-shell carry case
|Name||TeleVue - NP-127is 127mm, f/5.2 APO (Nagler-Petzval) Refractor - Imaging/Visual|
|Case||Custom Foam Fitted Hard Case|
|Focuser||2.4-inch, Focusmate dual-speed rack/pinion|
|Highest Useful Magnification||300x|
|No. of Elements||4 elements/ 2 groups|
|Optical Coatings||premium multi coated|
|Optical Design||APO (Nagler-Petzval) Refractor (Elements/Groups: 4/2)|
|Optical Tube Length||33.5"|
|Optical Tube Weight||15.4|
|Weight in Use||18.3 lbs|