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NP127is - f5.2 Nagler-Petzval Imaging System Apochromat Refractor (5.0 inch aperture)

A discontinued model, this original NP127is was replaced by the more refined 2010 model NP127is.

TeleVue NP127is Apo telescope (50,948 bytes)
Above: TeleVue NP127is telescope optical tube assembly with dew cap retracted. Provided with carrying case although this is not shown.
Note the TeleVue Focusmate™ extending off the Focuser. The protrusion at front is the knob for the thread-on Lens Cover (85,447 bytes).
Click on image to see enlarged view (237,040 bytes).


Al Nagler finally revealing his new telescope at Company Seven (111,487 bytes) The TeleVue NP127is is a first rate f5.2 flat field, four element apochromatic refractor that evolved from the original 127 5 inch Apo telescope. These have been engineered for astronomers who seek that very high performance and versatility that can be provided only by fast apochromatic refractors. The NP127 and NP127is telescopes perform identically in terms of visual applications, but the NP12is brings features that have direct impact on the telescope's suitability for astophotography and CCD imaging while taking nothing away from its visual usefulness and portability. In the Spring of 2006 TeleVue discontinued production of the original NP127 telescope in order to focus their production resources on building the NP127is.

Left: Beaming with the pride of a new father, Al Nagler finally reveals the original NP127 telescope to the public at Company Seven's showroom 30 January 2003 (111,487 bytes).

The 'is' suffix indicates defines this as one of TeleVue's recently developed 'Imaging Systems' series telescopes, produced to suit to the demands of those who in addition to visual uses are also seeking an astrographic instrument with features more commensurate with instruments of this higher performance class. The NP127is telescope is provided with a more massive 2.4 inch Focuser than the NP127, this provides greater payload handling and longer focus travel; valuable traits for those who may wish to attach devices in line including a Color Filter Wheel with CCD Camera for example, but more about this later. The Imaging System concept revolves around Televue's vision to develop an integrated, sole source, comprehensive solution for CCD imaging and astrophotography. This consists of numerous 'is' series accessories tailored to meet the needs of almost anyone who is pursuing CCD imaging in particular.

The origins of the 'is' Imaging System as explained by Al Nagler:

    "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 TeleVue Imaging System ("is") telescopes, we have refined our instruments and optional equipment beyond anything a CCD chip has seen. We started small (literally) in 2005 with the TeleVue-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

Company Seven was concerned but understanding about TeleVue's decision to discontinue the NP127. The NP127is is no doubt a great telescope of the same physical and focal length as the NP127, and the NP127is weighs only about 1-1/3 pounds more than the NP127. But our staff sensed that the majority of those who bought the NP127 from Company Seven chose it because it is a comparatively lightweight, compact and versatile 5 inch Apo that would be used by them mostly for visual applications: visual probably 95% of the time by 95% of the buyers. However, TeleVue determined there is more of a demand for telescopes of this high performance and cost among those who are moving into film astrophotography or CCD imaging. The NP127 sold most recently in 2006 with accessories for $6,250. While the optical tube alone of the NP127is cost $6,985. If one adds the cost of the 2 inch mirror diagonal and mounting rings to a NP127is, and then subtracts a fair estimate of the cost to add a geared focuser to the original NP127, then the difference in cost between the telescopes amounts to about $900. So the visual astronomer is paying $900 more for the NP127is whether or not he will benefit from the astrographic features of the NP127is. But given the recent greed and busts of the home sales and stock markets in the US, and the declining value of the US dollar and increasing raw materials costs, TeleVue probably could not justify keeping two similar instruments in production hence the 127is won out.

When we process and test each new TeleVue telescope we are impressed with the quality control, it is almost as if "Al knows this one is going to Company Seven". There are no other premium 5 inch Apos that are as versatile and flat-field right out of the box as is the NP127is. The NP127is remains a unique instrument in the marketplace, doing its own thing and doing it superbly well.


The NP127 series telescopes can be looked at simplistically as being an upscaled NP101 - TeleVue's highly regarded 4 inch Apo telescope. The NP127's advantages include ease of use and rugged portability similar to fast 4 inch Apos, with the proportionate increase in light gathering power and resolution over those smaller Apo telescopes. Fast Apos such as this are the most versatile of telescopes and they are also the most costly and difficult to produce well. Since the NP127 can provide visual fields of view as wide as 4 degrees at only 12X magnification, its practical uses include panoramic terrestrial applications. At the low to middle magnifications its 1.6X fold increase in light gathering power over the 4 inch Apos provides views and photographs of star clusters, galaxies and nebulae which are striking. While the telescope is also at home in the role of a high magnification, high resolution instrument for observing subtle details on the planets, moon, or double stars.

    "Our first impressions included surprise at how relatively compact this five inch refractor telescope is, and how well it performs across an incredibly broad range of useful magnifications. This telescope along with our Astro-Physics 13cm EDF f6 telescope, demonstrate how the advances in glass technology combined with the intelligent optical designs pioneered by Al Nagler of TeleVue and Roland Christen at Astro-Physics have pushed the performance and versatile practicality envelopes of these larger telescopes."

    Martin Cohen of Company Seven commenting about the NP127

The NP127is telescope fits neatly into the same 38-1/2 inch (98cm) long hard-shell carrying case as that provided with the TeleVue NP101 and 102 four inch Apos. In a departure from the conventional TeleVue case arrangements, the NP127is does not include a 2 inch Everbrite Mirror Diagonal and in its stead an IS Adapter is provided in a compartment within the lid of the carrying case; this space can accommodate several other accessories too. The air spaced objective of the NP127is is installed near the forward edge of the Front Cell to assure a good fit of the OTA in the TeleVue carrying case. We performed visual resolution tests of the NP127 telescope using a variety of eyepieces including the new TeleVue 2.5mm Nagler Type 6 (with and without a Barlow lens!), all results were consistently in line with our good experiences with the smaller proven NP101.

TeleVue developed a new, larger version of the popular "Gibraltar" Alt-Azimuth mount (illustrated below) which is intended for use with the NP127 telescope. The new head is engineered to fit onto the ash tripod as is now provided by TeleVue on the "Gibraltar" mount, but the machined aluminum trunnion and carriage arrangement has been enlarged to better accommodate the NP127 telescope. The ash wood tripod is functional and attractive.

Company Seven hopes to eventually display a NP127 telescope as another addition to our "Martin C. Cohen Memorial Telescope Museum Collection"!


TeleVue NP127 telescope at left on optional Alt Az Mount at right on Vixen GP-DX Equatorial Mount. Compared to other popular telescope designs (reflecting and catadioptric) the well made Apo refracting telescopes offer most natural, high contrast, and three dimensional views of the brighter objects. They also offer the greatest span of visible actual fields of view from low to extreme high magnifications. The shorter Apo telescope tube generally weighs less, impart less torque, and be managed on lighter weight and more compact mounts than achromatic telescopes.

Right: TeleVue NP127 telescope with Dew Cap retracted. At left shown attached to prototype TeleVue Alt Az mount with optional TeleVue "BinoVue" at rear and "Starbeam" accessories. At right shown on optional Vixen GP-DX German Equatorial Mount (25,009 bytes)
Click on image for high quality, enlarged view (189,357 bytes).

The fast and versatile flat field 4 and 5 inch aperture telescopes pioneered by TeleVue were the first to prove the value of using a refractor for deep sky observing and for imaging. Up to the early 1980's most refracting telescopes were relatively high magnification achromatic instruments typically of f12 or f15 with .965 or 1.25 inch diameter eyepieces which afforded relatively narrow fields of view. These telescopes were physically quite lengthy, and required taller and massive mounts to deal with their torque. By the 1980's optical glass and fluorite crystal lens design innovations made it possible to manufacture comparatively fast apochromatic telescopes of about f9. These faster designs combined with a capability to accept 2 inch diameter oculars permitted the wider fields of view (as much as 2.9x the area of 1.25 inch eyepieces) better suited to deep sky observing. Imagine being able to visit Paris to see the "Mona Lisa", and upon entering the gallery you are fitted with an eye patch on one eye and a soda straw attached over the other - you would be able to see any small area of the painting and as closely as you wish, but you would never be able to see the entire painting - that is life with most other telescope designs! Viewing through a fast Apo provides an experience where you are more often able to view the entire painting.

When comparing a 4 or 5 inch Apo to a mirror or catadioptric telescope in terms of detail and field of view, one could not build a large enough mirror telescope to rival the refractor without having so large an aperture that the field of view observed through the mirror systems would be comparatively narrow - this is where the Apos are unrivaled. And to attain the upper limits of magnification for studies of the planets, double stars, etc., one can simply employ any of the new TeleVue high performance short focal length eyepieces. Or with a negative lens in the form of a TeleVue Powermate (available in 2, 2.5 or 4X), the NP127 becomes a compact high resolution platform outperforming much larger instruments - which most of us do not wish to carry out too often!

It was an original first generation TeleVue "Renaissance" telescope (Serial No. 1019) evaluated in the March 1985 issue of "Modern Photography" magazine that earned "excellent" ratings on resolution tests, and "High" ratings for contrast with praise that included "with image quality beyond ordinary camera lens". Knowing the new NP101 and now the NP127 reflect dramatic improvements in the state of lens making technology, we can only wonder how such a modern telescope might be reviewed. And to our surprise in 1986 "Audubon" magazine rated the original 4 inch "Renaissance" as the top refracting telescope in a comparative survey of birding telescopes (the "Questar Field Model" a compact Maksutov-Cassegrain telescope was rated top choice over all); but we found it hard to believe that too many birders would haul a 4 inch Apo telescope very far - until the ultra compact NP101 arrived.

While some of us recall the limited production TeleVue 140 telescope of some years ago, the NP127 and NP127is are closer to being an evolution of the NP101 which is a sixth generation TeleVue four element design. The design follows the original TeleVue 5 inch "MPT" system introduced in 1982, the beautiful brass 4 inch aperture f5.5 "Renaissance" telescope introduced in 1984, the Genesis 4 inch f 5 telescope of 1988, and the "SDF" 4 inch f5.4 of 1993, and the 101 and Renaissance 101 telescopes of 1996. Al Nagler's patented four element designs are based on the original "Petzval" concept, this is an arrangement of refractive elements where a two element air spaced objective lens housed at the front of the telescope pass the light through to a second doublet lens at the rear of the telescope. The doublet lens group functions to reduce the effective focal length and to reduce or eliminate curvature of field.

    Compact and rugged, versatile and high resolution - the reasons why well made fast Apos are the choice of demanding visual astronomers.
TeleVue telescope cross section drawing
Above: Typical TeleVue Petzval telescope optical arrangement; 1. air spaced doublet objective, 2. mounting collar, 3. doublet lens, 4. focuser.
Options shown include: 5. "Everbrite" 2 inch mirror diagonal, 6. 2" to 1.25" reducer, 7. eyepiece (optional)

In prior TeleVue telescopes one could in theory remove the rear doublet lens and use the telescope with the objective lens alone in place. But the NP101 and NP127 are a departure from traditional TeleVue Petzval derivatives. Incorporating TeleVue's best air-spaced special dispersion doublet lens with what appears to be a simple doublet telecompressor/field flattener, the NP127 provides flat field wide angle views and the oversize rear elements of the NP127is provide coverage beyond that required solely for use with eyepieces. This is a complicated design where neither lens group can function independently without the other to form a good quality image.

Accepting 1-1/4 or 2 inch accessories including the highly regarded TeleVue Radian, Nagler and Panoptic eyepieces, the NP127is provides visual magnifications as low as 12X and a tack sharp field of view of as wide as 4 degrees are possible! A multi layer anti reflection coating process of the lenses, and on all the TeleVue eyepieces prevents light reflection off the surface of, or between the lenses. The result is a very fast, wide and flat-field system so well corrected that panoramic nature or star and planetary images are breathtaking. A collapsing lens shade aids portability. Its' uses include birding, CCD or video imaging, and film photography as well as visual and astrometric astronomy.

The TeleVue NP101 and the NP127 series telescopes are the first large TeleVue Apochromatic refractors which Company Seven found to be truly competitive if not superior in optical and mechanical performance to the best Apos ever made. They occupy a unique niche in the telescope inventory since no other telescopes exactly duplicate their out of the box versatility and ease of use. These telescopes provide false color-free, sharp, clear and high contrast images. And since the best apochromatic refractors are among the most difficult and costly in raw materials to make consistently well, these Apo refracting telescope will cost notably more than competing designs - but the waiting lists and high resale values testify to the confidence that the astronomy community has in telescopes such as these.


TeleVue NP127is Front Cell w/Lens Cover. The objective lens of the NP127is is of an air spaced doublet design where two lenses (crown and flint) are matched to work as one; the positive element is of a fluorocrown substitute with special dispersion glass. In fact this design allows excellent color correction without annoying purple or crimson fringes (secondary color) or spherical aberration common to less sophisticated achromatic refractors, and is better than a number of older triplet and modern doublet apochromat designs. A matched doublet lens group at the rear compensates for some design characteristics of the objective lens. The system provides a flat field, wide angle capability. Spherical correction is very good also with the large air space of the objective contributing to this correction. The stars appear as intense diamonds contrasted against a black velour background. And the major planets are presented with changing features from night to night, and in their natural colors. Daytime objects viewed at commonly used magnifications will appear quite three dimensional and sharp and contrasting.

Left: TeleVue NP127is Front Cell w/Lens Cover. Note the unprecedented transparent lens cover, this makes it lighter weight than a fully machined cover - and adds some "way cool" factor (68,652 bytes).
Click on image to see enlarged view (209,969 bytes).

The system's air to glass surfaces have a multilayer antireflection coatings that improves overall light transmission across the visual wavelengths and from 400nm to well beyond 700nm. The coatings used on the NP127is telescope are engineered to match the characteristics of each glass type and curve radii. This process improves color rendition, achieves a dramatic increase in image contrast and actual light transmission, with a corresponding reduction in flare which might otherwise originate by internal reflections. Overall the complete four lens system provides about about 300 times the light gathering power of the unaided human eye - about the same as typical 5 inch doublet systems. On most nights, the settling down time for the optics will be the order of minutes; from room temperature to freezing it rarely will require more than 45 minutes to an hour for the optical tube assembly to acclimate.

The lenses are so well figured that the consistency between telescopes is quite good, and each is capable of operating at very high magnification cleanly (even with optional "Barlow" or "Powermate" lenses). This telescope crosses that threshold necessary to routinely obtain meaningful views of the planets, showing several bands and their shades of color (from creamy whites to beige, tan, browns) on Jupiter - observe the four largest moons of Jupiter and their shadows cast on the surface as distinct discs as they transit across the planet at times eclipsing one another! Study the Cassini division and banding on Saturn, the polar cap and dark markings on a fiery red Mars. With an eyepiece that shows 1/2 degree field or so (such as a 5 mm "Nagler" or 6mm "Radian") take a walk on a apparently three dimensional Moon, resolving objects as small as 3.5 km in diameter. Or follow the lunar terminator throughout the phases; optional neutral density filters are offered by Company Seven to attenuate brightness and make observing more comfortable.

With an optional white light solar filter (such as our Baader AstroSolar film) observe Faculae and Sunspots on the Sun! With our optional Hydrogen Alpha filters (either the DayStar ATM or University series) observe Faculae, Sunspots, the peach-fuzz like photosphere surrounding the Sun, and the sheer curtain-like Prominences as they erupt from the Sun out into the blackness of space!

A matched wide angle ocular reveals the NP127is's extraordinary wide field of view capability, and can easily reveal the entire Messier Catalog of deep sky wonders. It is also just as well employed for panoramic viewing of a seashore or countryside. Imagine a telescope that at a dark sky site has the combination of resolving power and field of view to sweep the Milky Way, see the Double Cluster in Perseus (NGC-869) in their entirety, find the Andromeda galaxy (M-31) and see it's ellipsoid shape and several dust lanes, and with no doubt see the distinct forms of large Nebulae such as the Veil and North American Nebulae! With a wide angle eyepiece the TeleVue NP127 can reveal all three stars of Orion's belt, closer in it reveals the jewel like stars of the Trapezium - a birthplace of stars, with a sweeping wisps of greenish gas clouds surrounding it.

Studied under a higher magnification M13 (the "Messier" catalog Hercules star cluster) takes on a three dimensional "salt and pepper" appearance even from suburban skies on a clear night. By the time one finds a large enough aperture catadioptric, reflecting, or achromatic refractor to see similar detail then one can only see a fraction of their area due to the relatively high focal length of these competing telescopes; with other telescopes it would be something like trying to observe the night sky through a straw!

    Viewing through a fast Apo is an experience where you are more often able to view the entire painting.

In fact, one of the finest advertisements ever published for a multi purpose telescope concept is the book Deep-Sky Companions: The Messier Objects where the author Stephen O'Meara sought to keep the drawings relevant to the amateur. To produce the highly detailed drawings of these celestial objects Stephen chose to observe with the second generation TeleVue "Genesis" telescope (4" aperture, 500mm f5) which as glass technologies advanced has since been replaced by the improved TeleVue apochromatic telescopes. This book has become one of our best advertisements for the versatile, readily transportable fast 4 inch (10cm) refracting telescopes. Similarly to keep things simple, and relate as much as possible to the average amateur observer Stephen chose to use the telescope on the simple but sturdy TeleVue "Gibraltar" alt-azimuth mount with Ash Wood tripod. He equipped the telescope with only a modest selection of accessories: TeleVue 22mm "Panoptic" eyepiece (providing 23X, 2.85 Degrees Actual Field of View), a original 7mm Nagler eyepiece (71X, 1.08 AFOV), and a TeleVue Barlow lens to increase the magnification by 1.8X. In fact Stephen O'Meara recently commented "the TeleVue NP101 would now be my telescope of choice". Read that book and then consider the 60 per cent improvement in light gathering power that the aperture advantage alone of the NP127 should provide!

The NP127 compares favorably against many telescopes in field of view, but in fairness the cost of the NP127 like most other serious Apo's (equipped with either an optional Alt-Az or Equatorial mount) is positioned at a higher cost than most amateur telescopes. And as a practical matter for some applications in astronomy the nominal match of the NP127 exit pupil to an average dark adapted human eye will be obtained at magnifications of between 18X and 25X. The best performance and viewing comfort will be obtained at all magnifications if a wise choice of good quality oculars is made however since the NP127 telescope incorporates a field flattening element then it is technically compatible with several of the simpler eyepiece designs. Most of our NP127 customer employ an optional good quality Barlow lens or a TeleVue "Powermate" amplifying (negative) lens, or optional wide angle "Nagler" or long eye relief TeleVue "Radian" ocular will usually be put into use to attain the highest usable magnifications which are necessary for observing small bright objects including planets, and close double stars. But we can think of little else that could be more awe-inspiring than wading into a star cluster or nebula with the NP127is using a TeleVue 13mm Ethos eyepiece viewing 2 Degrees of sky at 51X!

For film photography, the telescope (with our optional camera adapters) becomes a super sharp 660 mm f5.2 ultra telephoto lens, showing about 3.7 degrees across the diagonal of a 35mm camera film plane. And for CCD imaging operations the telescope at prime focus can show an area about 0.7 degree across the diagonal of a common 2/3" detector (such as that employed on some of our SBIG CCD systems. Optional techniques and hardware permit imaging of galaxies, nebulae, the planets, or of wildlife.

The NP127is can operate on any of a number of suitable optional German Equatorial mounts including:

For simple visual uses with the NP127 TeleVue developed a higher capacity variant of the popular our TeleVue "Gibraltar" portable alt azimuth mount and tripod.

This is a telescope one may not outgrow, but since most of the accessories that one would buy for this telescope are upwardly compatible with any larger telescope that one is likely to buy at Company Seven one will not feel trapped by the cost of accessories for the second telescope. It has been argued by many experienced observers that while no one telescope can do it all, the Apo refractor is most versatile. And it can be complemented by a large 18 to 22 inch aperture Dobsonian telescope such as those we offer by AstroSystems.


The telescope objective (front) lens cell, retracting dew shield, lens cover metal frame, focuser housing, 2 inch mounting collar and other fittings are of bead blasted aluminum construction, entirely black anodized in a lustrous finish. The barrel is powder coated in a textured neutral Ivory; the powder coat feels like a thick textured smooth plastic covering which is quite comfortable to manage even in extreme cold or damp climates. The interior of the optical tube assembly is lined with an antireflective covering unique to TeleVue telescopes, which is then finished with anti reflective black paint. Aesthetically it is a good looking instrument that inspires confidence and pride of ownership.

The NP127is has a fully machined aluminum front cell to house the objective lens. The objective lens is permanently aligned to the barrel as is the focuser assembly. Unless subjected to gross abuse this telescope will provide many lifetimes of service with no need for any other than cleaning of the front surface of the objective lens using common camera lens cleaning techniques. Its construction is extremely rugged to allow it to withstand all the handling that is typical of airline travel. However, some caution should be practiced not to damage the focuser pinion of any telescope; our experience with this focuser is that with routine handling this will not happen and in its hard shell case is routinely transportable. The NP127is does incorporate a retracting Dew Shield/Lens Shade.

Also provided is a thread-on Lens Cover of machined aluminum outer frame with a transparent acrylic window. A hand knob is provided at the center of the window with a rubber grip grip ring. This design notably reduces the weight of the otherwise heavier machined aluminum cover. And it is another innovation so far unique to the NP127!

New Focuser: The TeleVue focusers continue to be among the smoothest and easiest to operate focusers in production. The aspect that differentiates the NP127is most from the NP127 is its new precision focuser. The goal of this change is to:

  • provide the imaging astronomer with a larger 2.4 inch clear aperture to facilitate coverage with no noticeable vignetting of formats up to the 35mm (36mm x 24mm x 43 mm across the diagonal). In order to avoid mechanical obstructions to the light path which would appear as vignetting or gradual dimming of the image nearing the periphery the draw-tube of the Focuser is 76mm diameter, this is a larger aperture inside the telescope than at its 61mm departure point. The interior opening at the draw-tube has an area on the order of 7 square inches (yes circular Winking Happy Face) and this tapers down to an area of 4.53 at the departure point. We have experience with imaging cameras with detectors up to 52mm across on the NP127is that have provided spectacular images with Flat Fielding.

  • improve the rigidity and payload capacity of the focuser so that it can smoothly manage the weight of CCD cameras even with accessories such as Color Filter Wheels and robotic helical focus attachments.

With its larger diameter draw-tube, the NP127is can accept either the 2.4 to 2 inch diameter accessory holder (provided and as shown in the images), or it can accept a variety of fittings to accommodate film and CCD imaging cameras. A basic Imaging Adapter is provided with the telescope and is stored in a compartment in the lid. This adapter is simply a precisely machined metal ring that is threaded to accept any one of a number of the fittings made by TeleVue and third parties; this ring attaches onto the draw-tube of the focuser in place of the 2 inch accessory holder and either adapter are secured by means of the four set screws.

This focuser is a rack and pinion design with a tension/lock screws which helps to lock focus for uses including photography. The 1-1/2 inch diameter machined aluminum hand knob resembles the brushed aluminum mag wheels available for radio control model cars. The knob hand grips are rubber covered to facilitate operation in all extremes; even when wearing gloves all the controls on the telescope are easy to manipulate. The set screw has an easy to grip knurled head, this permits one to adjust resistance of the focuser to its draw tube thereby compensating for heavy loads that might otherwise cause an unintended shift of focus.

Focusmate™: In addition to this TeleVue has engineered their own dual speed geared focus control mechanism, the Focusmate™. This is an ungainly looking contraption that seems to take up way too much space hanging off the side of the telescope for our sense of aesthetics, and concerns of vulnerability. But in fact it works, it works very smoothly to provide both coarse and fine focus with a reduction ratio of 6:1 (six turns per revolution), and is easier to turn and smoother in its motion than some other devices we've seen, and Focusmate™ is reliable.

The Focusmate™ is provided with the telescope attached with the dual speed geared control knob at the right side of the telescope; the case is cut for this to be on the right side. It is a simple matter to remove and install the Focusmate so that the control is on the left side, and it is possible to also add the other components of the system to this but some change of the telescope orientation and cutting of foam may be necessary.

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!

T127is Focuser 1
TeleVue NP127is

Focuser with 2 inch accessory holder,
and Focusmate geared focus drive assembly
T127is Focuser 1
TeleVue NP127is

Focuser showing 127is Label,
standard knob is on left side as delivered.
C7 QC label at bottom of focuser
T127is Focuser 1
TeleVue NP127is

Focuser sowing 2 inch Port
the Rack is just visible as the
Drawtube has been withdrawn slightly

Table above: NP127is telescope 2.4 inch focuser detailed views.
Click on each image to see the enlarged view.

TeleVue NP127 Apo Telescope focuser 2005 (51,070 bytes) For comparisons, the focuser of the NP127is focuser has 1.44X the clear area of the Televue 2 inch focuser. The new focuser is much more rigid than the 2 inch focuser provided with the original NP127 telescope and so it can handle the increasing weight of CCD cameras and their accessories.

The focuser of the NP127is also has slightly more focus travel so that it can accommodate a wider range of visual and imaging accessories.

Left: TeleVue NP127 telescope focuser with draw tube fully retracted, showing the 2" diameter no mar clamp lock mechanism (51,070 bytes bytes).
Click on image to see enlarged view (133,406 bytes).

This focuser is particularly beneficial to those who entertain CCD or film imaging with the heavier cameras; this design was tested so far with loads including an Apogee U9000 and the SBIG STL series CCD camera which approach 5 lbs. (2.3 kg). The greaseless draw tube arrangement of the NP127is is more sophisticated in its machined arrangement, so that it has fewer bolt on parts to work loose. There is a clamp ring within the focuser body surrounding the draw tube, this provides uniform and more secure tension with less image shift applied by either of two set screws on the focuser housing drawing in to applying pressure onto an internal pad. The end ring is incorporated into the machined draw tube so there is no longer any way the payload can tilt at the end of the draw tube, and this arrangement incorporates a non-marring clamping mechanism to hold the various adapters. For convenience and safety the NP127is focuser has four clamp knobs on the draw tube accessory clamp provided so that the observer may find at least one lock convenient to reach regardless of where the telescope is pointed. We measured the focus travel distance of this focuser draw tube as 2.44 inches (62 mm), about 10 mm greater than that of the original NP127.

Since the is series telescopes are geared for CCD imaging with larger formats CCD systems, and since the plane of a CCD may not perfectly parallel to the optical axis of the telescope across the focuser of the NP127 makes the provision to tilt it and bring the attached CCD into a more perfect alignment. We know of no other production telescope in 2006 that has this mechanism. The process if it is ever needed would be best performed with the CCD camera attached in its desired rotational configuration (rotating the camera on the focuser may change the solution so one needs to be able to rotate the optical tube with the CCD to change framing), with the work performed in a clean controlled environment on a suitable test target. The process involves adjusting the "push pull" focuser bolts at the end of the draw-tube. This must be performed meticulously and while evaluating the changes to the image. Once the best focus is attained then the focuser is locked in place. And remember if a CCD camera necessitates a focuser tilt, then upon changing to another camera there will likely be a need to adjust the focuser back to its original configuration or repeat the process. If the CCD is notably out of alignment in its housing then Company Seven's advice is return the CCD camera for exchange. Also note the NP127 optical tube is machined mostly of aluminum and so temperature changes will alter focus over time. While most people taking relatively short exposures will do well with the standard focuser, Company Seven recommends our customers who attempt long exposures should employ a temperature compensating robotic focuser.

TeleVue NP127 Apo Mounting Rings (81,225 bytes) Carrying Case: Also included with the NP127is telescope is a die cut, foam lined hard shell carrying case with latch closures. This very lightweight formed ABS case has and compartment in the lid with a hinged door revealing extra space to accommodate the camera or visual adapter. The attraction of the case is its compact, non marring form (rounded plastic corners do not punch through car seat coverings), and its light weight. However this is also its Achilles Heel: this case is NOT an Airline Transport Association (ATA) approved shipping case, and one would be foolish to trust their $7,000 investment in this case alone in any adverse environment.

Right: NP127is Carrying Case has dual handles, side by side (81,225 bytes).
Click on image to see enlarged view (258,164 bytes).

The carrying case is similar to that provided with TeleVue 4 inch refractors and with the NP127 however, the case for the NP127is is given away by the two carrying handles installed side by side near the middle of the case. These handles reduce the chances of a sole handle giving way, and it also reduces the chances of accidentally dropping the telescope out if the latches are accidentally left unfastened.

At 38-½ inches in length the case will fit technically into the overhead storage area of most commercial aircraft (one exception being the L-1011) however, many airlines will not permit such an 'oversize' package on board. Even if they do you will not be too popular with fellow passengers when you take up an entire overhead space, and so you might ask a Flight Attendant to store the telescope for you - possibly in the garment bag storage area. Company Seven has made durable, custom tailored, padded form fitted carrying bag for customers who bought their NP127 from us. This lightweight padded bag zips to fully enclose the TV127is in a compact form, with its carrying strap a number of our customers carry the 34 inch long cylindrical pouch with telescope onto the aircraft where they are off to enjoy remote skies with 5 inches of Apo! Some extra care must be taken to protect (if not remove) the Focusmate™ from impact since this is not a rigid case.

The telescope in its standard hard shell case is well padded and then packaged for delivery within one box, and then this is placed into another box. You should consider the practicality of simply shipping telescopes (and mounts) such as this ahead by a priority air service (FedEx, UPS, U.S. Mail, etc.) if you are concerned about cutting down the number of bags you can carry on or check in. Furthermore, shipping the telescope could reduce risks of loss or damage in shipment, and inconvenience and risks of managing bags through airport terminals. If you wish to travel with your NP127 then ask Company Seven about out wonderfully engineered Airline Transport Association transport (for check-in) and shipping cases for telescopes, mounts, and accessories.


TeleVue NP127 Apo Mounting Rings (51,070 bytes) Attachment Hardware: The NP127is is ordered 'ala Carte', this is to say that nothing much beside the OTA and the case are provided. This gives the end user the choice of how they prefer to install the telescope and what they wish to add on to the telescope: one does not pay for what one may not use. Company Seven offers several third party and custom options for customers who buy their NP127is from us, and you may contact us to discuss these choices and applications.

TeleVue offers a set of optional hardware consisting of two (one pair) conventional style clamp-on mounting rings. Each is a circular split ring machined of aluminum and black anodized with a lining of fabric. The ring halves are bolted together by means of a hex head bolt on one side, while on the other side is a manual tension adjustment knob. This arrangement permits one to adjust the grip of the rings on the barrel with no tools so that the telescope may be easily moved back and forth to compensate for changes of accessory loads that may affect the balance of the telescope on a mount. A machined aluminum bar is bolted on spanning the two mounting rings across the top to add extra rigidity, this does not seem to be necessary but no astronomer ever complained about too rigid a support system. At the 10:30 and 1:30 o'clock positions on the top of the collar there is a dovetail platform to accommodate a variety of TeleVue options including the "Starbeam" sight, or a "Piggycam" piggyback photography mount, and a universal mount to accept common 50mm finderscopes. The NP127 telescope so fills the carrying case that a Starbeam sight must be disconnected from its provided base to fit the telescope back into the provided case.

Right: TeleVue NP127 telescope optional MRS-5000 Mounting Ring set with stiffening bar (58,808 bytes).
Click on image to see enlarged view (156,239 bytes).

A machined aluminum mounting plate is provided installed at the 6 o'clock position on the mounting rings. The rectangular plate is provided with two 1/4 inch 20 tpi stainless steel studs installed with wing nuts which makes the NP127 ready to slip onto the TeleVue alt azimuth mounts. The mounting plate features several other tapped and threaded holes to facilitate installation of the NP127 onto other mounts or plates.

This ring and bar set is a good arrangement for those using the telescope for applications including visual, or light duty astrophotography or CCD imaging which demand extremely rigid support of the telescope. However, for those of our customers interested in employing heavier piggyback loads atop the NP127 (guide telescopes, large finder, etc.), then Company Seven can provide optional alternative rings and mounting plate hardware.

Mirror Diagonal: If you intend to use the NP127is for visual uses, then it will be necessary to furnish the telescope with an optional mirror diagonal. One good choice would be the TeleVue 90 degree 2 inch diameter "Everbrite" precision mirror diagonal (1/10th wave P-V quoted). This diagonal has a durable and highly efficient reflective coating. The interior is fully anti reflection ribbed and coated. The male 2 inch barrel of this diagonal is threaded to accept 48mm photo and visual filters.

Left: TeleVue Everbrite 2" Mirror Diagonal and TeleVue 2" to 1.25" Reducer showing no mar clamp lock mechanisms (64,909 bytes).  TeleVue Everbrite Diagonal and 2

The "Everbrite" mirror features a high technology dielectric coating developed originally for military optics used in hostile environments such as blowing desert sand. This TeleVue 2 inch diagonal has no aluminum or other reflective metal coating. Instead, the reflective element consists of about fifty layers of thin film oxides similar to those used in antireflection coatings. These coatings are deposited into the glass by an electron beam evaporator at a high temperature. The result is that reflectivity is above 99% over the entire 4000 to 7000 Angstrom photo-visual range. Thin film coatings have extremely low surface scatter compared to aluminum or enhanced aluminum coatings; examination with a laser source shows approximately a five fold improvement in surface scatter. This coating will provide optimum performance and a lifetime (or more) of use.

The mirror diagonal provides a comfortable viewing position for the observer by diverting the image at the rear of the telescope off axis by 90 degrees to the side, with minimal degradation of image quality. The view when using the telescope as it is provided will appear to be right side up, and is reversed left to right; this is not usually a problem for astronomy or nature observing because the image quality provided by the high quality mirror and 2 inch diameters panoramic oculars is exceptional. While Company Seven does offer optional 45 degree inclined image erecting prisms, these prisms can only accommodate 1.25 inch diameter oculars. Furthermore, the erecting prisms will not provide image quality to equal that of a good mirror diagonal; this is particularly perceptible at higher magnifications. However, for moderate to medium magnification applications where one needs correct images (such as to read numbers, etc.) then the optional prism should be suitable.

A TeleVue 2 inch to 1.25 inch reducer adapter is furnished to permit the use of 1.25 inch diameter accessories. The reducer is engineered with a collar to prevent long barreled eyepieces even with one filter attached from "bottoming out" against the mirror. This diagonal permits an observer to employ any of a broad selection of 2 or 1.25 inch diameter oculars. The lock screw with a knurled head that is at the proximal (to the operator) end of the female 2 inch barrel adjusts tension to retain accessories such as the 2 to 1.25 inch reducer or lenses.


Clear aperture: 127 mm (5")
Focal length: 660 mm (26.0")
Focal Ratio: 5.2
Resolution (visual): 0.91 arc seconds
Resolution (photo): 1.0 arc seconds
Coatings: Optimized Multilayer
Useful Magnification range: 12x to 450x
Tube assembly: Powder coat finish, aluminum tube; fully baffled, permanently aligned cell construction
Focuser: 61mm (2.4") rack and pinion
Focuser Aperture: 50.85mm (2.0")
Focuser Travel (2007): 62mm (2.44")
Optical Tube Length: 83.8 cm (33 inches)
Optical Tube Length w/o Lens Cover: 85.2 cm (33-9/16 inches)
Telescope length with diagonal: 91.8 cm (36.2") dew cap retracted
Weight of O.T.A.: 7.0 kg (15 lbs. 6.6 oz)
Carrying Case Dimensions: 98 x 27 x 23cm (38-1/2 x 10-1/2 x 9-1/2 inches)
Shipping Weight: 15.5 kg (34 lbs. )
Shipping Dimensions: 101.6 x 33 x 25cm (40 x 13 x 10 inches)
35mm prime-focus field: 3 x 2.1 x 3.7 degrees @ f5.2
35mm field with optional 2x Barlow: 1.5 x 1. x 1.9 degrees @ f10.4
Eyepiece: Optional
TeleVue NP127is telescope as provided (19,306 bytes)
Above: TeleVue NP127is as provided by TeleVue including fitted Carrying Case, Photo and Visual 2.4 inch Adapters, Lens Cover.
The Carrying Case shown above is the original model, this has since been replaced by similar case but with two carry handles arranged side by side.

        * Specifications are subject to change without notice.

Additional Reading: we host numerous articles and users guides in our Library including:

  • PDF Icon TeleVue NP127is Operating Guide, 2006 Model, the illustrated eleven (11) page guide by TeleVue explaining the 2006 Model NP127is telescope and how to configure it for use with the numerous Imaging System accessories. This includes advice about what adapter(s) are required to employ the telescope with various formats of digital and film cameras and of popular astronomical CCD imaging cameras. Download is 3,359,713 bytes in Adobe .pdf format.


  • "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. The NP127 case does not have space needed to accommodate an installed Starbeam however, for storage or transport it is a simple matter to loosen three knobs to remove or attach a Starbeam.

  • Eyepieces: The telescope is not furnished with an ocular, this is a good idea since many customers moving up to a telescope of this class may already own similar eyepieces. Plšssl, Orthoscopic, traditional Erfle and wide angle eyepieces show sharp images only in the center of the field when employed with telescopes such as this. These are acceptable as long as you realize this limitation, and find this unobtrusive. If you object to less than perfect images at the edge of the field, then Company Seven recommends the TeleVue "Nagler", "Radian", or "Panoptic" eyepieces. These oculars provide the most clear, and flat field images and will bring out the most in your NP127 (and many other) telescope. A 35mm to 55mm focal length eyepiece can also make the main telescope also serve as your finder. Please refer to the brochure and the test report/data generated by Company Seven enclosed with our telescopes for descriptions of these items and additional accessories.

  • Barlow or TeleVue "Powermate" Lens: Company Seven suggests you consider any of a number of 1.25 inch or 2 inch diameter Barlow lenses that we offer to double or more than triple your magnification. Contact us for suggestions on how to to best meet your goals.

  • TeleVue 1.25 Inch Prism Diagonal: 45 degree 1.25 inch diameter precision image erecting prism diagonal with high transmission coating. This is a good choice for those who must have an image erect and correct left to right view, and who do not intend to use the telescope at higher magnifications.

  • Mounting Rings: Company Seven can provide customized hardware to facilitate installation of the NP127 onto third party mounts. Furthermore, we can provide hardware that will permit the installation of a finder, photoguide telescope, or larger piggyback camera or sensor payloads.

  • If a customer saves the packing boxes, then he might be able to actually ship the telescope ahead for a vacation in Hawaii, or some other paradise. But the cardboard boxes and the carrying case can not tolerate repeated abuse, or travel by common carriers. Company Seven does design and offer custom Airline Transport Association approved transport cases for those telescopes and mounts which we sell; one who travels quite a bit would find these to be cost effective protection, and convenient as well.

    In addition to our own ATA cases, Company Seven will offer optional padded soft cases to our customers in order to facilitate transport of the telescope.

As we do test each new NP127is that arrives at Company Seven and we generate a comprehensive report which will provide useful information about the photo and visual possibilities with your new NP127is. Nobody outside of TeleVue has a better understanding of these telescopes, and so Company Seven can provide personalized advice on how you may best accessorize the instrument. Here are some of the most popular oculars from which you could put together some assortment:

    Eyepiece Magnification Actual field of view Exit pupil
    35mm Panoptic 19x 3.4 degrees 6.7mm
    31mm Nagler Type 5 21x 3.6 degrees 6mm
    22mm Nagler Type 4 30x 2.7 degrees 4.2mm
    22mm Panoptic 30x 2.1 degrees 4.2mm
    19mm Panoptic 35x 1.9 degrees 3.7mm
    17mm Nagler Type 4 39x 2.1 degrees 3.3mm
    13mm Ethos 51x 1.9 degrees 2.5mm
    12mm Nagler Type 4 55x 1.5 degrees 2.3mm
    9mm Nagler 6 73x 1.1 degrees 1.7mm
    7mm Nagler 6 94X 0.84 degrees 1.35mm
    6mm Radian 110x 0.55 degrees 1.15mm
    5mm Radian 132x 0.6 degrees 1mm
    3mm Radian 220x 0.3 degrees 0.6mm
    2mm Nagler Zoom 330x 0.17 degrees 0.4mm

    * The telescope is capable of operating at magnifications greater than listed in this briefing above.
    Contact Company Seven for additional advice about outfitting the NP127 for high magnification observing.

  • Company Seven's ATA Transport/Shipping Case: ship and protect your investment! The lightweight plastic shell case provided by TeleVue with each optical tube assembly is a reasonable balance of economy and performance for routine storage of a telescope in a temperature and humidity controlled environment. However, if you plan for long term storage, or if you intend to ship the telescope by commercial carrier or transport it as check in baggage on an airliner then your peace of mind and telescope will both be better served with a custom engineered solution - an ATA case by Company Seven.

    TeleVue NP101 telescope in optional Company Seven ATA case (138,840 bytes)

    Above: Company Seven ATA Case custom fitted for a TeleVue NP101 telescope and accessories (138,840 bytes).
    Click on image to see enlarged view (240,578 bytes).

    Features include:

    1. custom fit to accommodate the telescope optical tube with or without accessories (Rings, Focuser, etc.)
    2. hand fitted velour lining over foams of varying densities to deal with anticipated loads
    3. weather resistant construction - engineered by our expert craftsmen
    4. tamper resistant combination lock and hasp
    5. Fedex/UPS label plate
    6. choice of interior and exterior hard shell material and colors

Please contact Company Seven for additional information and pricing.

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