Tele Vue NP101 User Manual
®
Tele Vue
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Operating Guide
540mm f/5.4
4-ELEMENT APO REFRACTOR
Thank you for purchasing the Tele Vue-NP101. It has been our pleasure to craft this fine instrument for
you. Though instructions for use are as simple as mounting the scope, removing the lens cover, and
inserting an eyepiece, please take a moment to review the information here.
Thirty-plus years ago Al Nagler took Petzval’s portrait lens concept using widely spaced doublets,
and patented a fast telescope design version for the purpose of testing eyepieces. The 5” f/4 MPT
(Multi-Purpose Telescope) with its fast speed, wide and flat field, led to a series of continuous improvements, primarily in color correction. The “Halley Commemorative,” 4” f/5.5 started the parade where
more advanced glasses including special dispersion, fluorite and fluorite substitute glasses brought steady
improvements. The 4” f/5 Genesis employed fluorite in the rear doublet and the SDF version at f/5.4
and subsequent Tele Vue-101 version brought us closer to perfection. Maintaining the f/5.4 speed while
reducing tube length in a totally new design, with new glasses allowed virtually ideal color correction and
improved field flatness. The NP101 (Nagler-Petzval) is the ultimate culmination of 30-years of refinement
toward optical perfection. Al’s “spacewalk” dream from his 1960’s NASA simulator days is yours to live.
Bon Voyage!
WARNING: NEVER try to look at the sun or point the telescope toward or near the sun without
professional solar observing equipment rigidly secured in front of the objective lens. When
observing the sun with the proper filters, use only the Tele Vue “Sol-Searcher” (SSF-1006) for
finding the Sun. Remove any finding devices such as Starbeam from the telescope. Instant and
permanent eye damage may result from viewing the sun directly, even during a solar eclipse, or when
viewing through thin clouds, or when the sun is near the horizon.
Standard Features - sliding dew shield, screw-on lens cover, 2” focuser with 10:1 reduction, 2” Everbrite
diagonal, 2” to 1¼” adapter, ring mount and custom hard-shell case.
Mounting - For attaching the Tele Vue-NP101 to any Tele Vue mount, you will receive the two ¼-20 studs,
wing knobs, Allen wrench and complete mount assembly instructions with the mount. Tele Vue makes various adapter plates for popular German equatorial mounts. Please consult your dealer.
Finders - We particularly recommend using the Starbeam reflex sight (part# SFT-2003), which attaches to
the Ring Mount. The telescope will fit in the case with the Starbeam attached. Movement of the mount ring
may be necessary. The Quick Release Universal Finder Bracket (QFM-1008) holds a traditional 50mm
finderscope and also attaches to the mount ring channels.
Terrestrial Viewing Considerations - The Tele Vue 55mm Plössl or 41mm Panoptic in a 2” diagonal will
provide the maximum true field of 4.9°. This can serve as a finder, for rich field viewing or for terrestrial
use. (Image is upright, but left-right reversed using diagonal mirrors.)
Tele Vue
Visionary
®
32 Elkay Dr., Chester, New York 10918 (845) 469-4551. televue.com
However, Tele Vue developed the 1¼” 60° Everbrite Diagonal (part# DPC-6012) specifically for
terrestrial observers who appreciate the highest levels of image performance. The 60° angle is far more
comfortable for terrestrial observing than the standard 90°, and the 99% reflective Everbrite dielectric
coating gives the truest color rendition of any mirror or prism, and is sharpest at the highest powers.
For correct left-right viewing, use the Tele Vue 45° erector (part# AMI-0011). Barlows, Powermates
and Bino Vue are not recommended with the 45° erector. For 1¼” diagonals and prisms, the 32mm
Plössl, or 24mm Panoptic offers the maximum field. 2.9° at 17x and 22.5x respectively.
Getting Acquainted with the Tele Vue-NP101
1.1 Optical tube assembly
The optical tube consists of an air-spaced doublet within the front cell. The front cell is attached to the
tube via three alignment locking screws which you’ll see when sliding the dew shield forward. (Warning:
Loosening these screws will ruin the collimation.) The rear doublet, making up the rest of the objective is
housed in the cell that threads between the back of the tube and the focuser. Do not stick any long objects
into the focuser or you will hit the rear most lens surface.
1.2 Focuser
The 2” focuser is a custom fitted rack and pinion type which is capable of supporting the heaviest accessories without slipping. The left side focuser knob and inner knob on the right side are a 1:1 ratio. The outer
(smaller) knob on the right side is a 10:1 ratio, which will help in fine focusing for planets and photography.
The two tension screws on the top of the focuser body can be adjusted to add resistance when
using heavy eyepieces or cameras. These tension screws tighten against a brass clamp ring, which then
cinches down on the Teflon sleeve in which the draw tube slides. For photography it is not necessary to
tighten beyond the need to keep a camera stationary. Even when sufficiently tight, the focuser knobs can
still drive the draw tube.
The focuser body is pre-drilled to accept the Digital Indicator Kits (RMK-2002/RMF-2003) for focus
accuracy down to 1-micron. The dual speed pinion assembly is pre-drilled to mount the 10:1 Focusmate
Driver (FDF-2004). (See section 1.5 Photography)
The two lock screws in the end of the draw tube also tighten against a brass clamp ring for extra
holding power on the diagonal or other accessories.
1.3 Ring Mount
The Ring Mount permits easy telescope balancing. Simply loosen the “bat handle,” reposition the O.T.A.
and re-lock the bat handle. The Ring Mount base is blind tapped with three ¼”-20 threaded holes so
screws cannot hit the tube. The two accessory channels are tapped with #10-32 threaded holes.
1.4 Case
When opening the case, we recommend always lifting the lid while holding the handle. The lid opens a
Optional Accessories Shown
full 180° and holding the handle will give you a better grasp to insure that the lid doesn’t slip out of your
hand. The interior of the case was designed to store your scope with the optional Starbeam, Focusmate
Motor Driver and Digital Indicator Kit installed. To fit the Starbeam, you may have to slide your ring mount
so that the Starbeam fits in the lid of the case between the accessory bags.
Sliding Dew Shield
(retracted over Front Cell)
Tube
Ring Mount
Accessory
Channel
Bat Handle
Digital
Micrometer
Attachment
Points
2” to 1¼”
Adapter
1¼” Accessory
Focuser Tension
Knobs (2)
Lock Screw
2” Accessory
Lock Screw
Diagonal Lock
Screws (2)
Draw Tube
Diagonal
1:1 Focus Knob
10:1 Focus Knob
1:1 Focus Knob
10:1 Focus Knob
1:1 Focus Knob
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