Tele Vue TV-NP101is Telescope

Tele Vue TV-NP101is - 101mm, f/5.4 APO (Nagler-Petzval) Refractor, Imaging/Visual - is based on exemplary wide field of 4.9†­ and planetary visual scopes with added features to make imaging easier and more flexible.

The NP101 (540mm, f/5.4, 4") maintains its 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 the 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 our 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.

Concept: 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 ("is") telescopes, we have refined our instruments and optional equipment beyond anything a CCD chip has seen. (Reviewer Note.) 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.

We were 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. (Reviewer Note.) How? By applying the developments created for the Tele Vue-60is to the new NP101is and NP127is and then going beyond.

The NP101 (540mm, f/5.4, 4") and NP127 (660mm, f/5.2, 5") maintain their 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 (Reviewer Note.) so the corners of the newly brightened edges would virtually be as perfect as the center of the field.

Next, to take full advantage of the larger lenses, we developed a larger focuser and draw tube having a 3" front aperture and 2.4" rear aperture. This eliminates any restriction of the larger diameter converging light cone. We build and test the rack and pinion focuser to hold 12 lbs. of weight, yet still permit extremely fine focusing control via a 10:1 dual speed pinion assembly. 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 our 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. (Reviewer Note.)

The Focusmate 10:1 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.

Tele Vue has been known for producing visual instruments "even better than you imagined." We aim to achieve the same with our imaging equipment. Our dedicated local machinists and in-house staff are as committed as ever to deliver on these quality and performance goals. (Reviewer Note.)

TV - NP101is Imaging System Accessories:

Focal Path: Optical Accessories:

• LCL-1069    Large Field Corrector, NP101/NP101is/NP127is
• NPR-1073    0.8x Reducer for NP Scopes
• AFT-1105    48-mm Filter Adapter for 2.4"
• A2A-1107    2.4" Adapter for 2" Accessories          

Focal Path: Camera Adapters

• TRG-1072    Standard T-Ring Adapter for 2.4"
• CWT-2070    Canon Wide T Adapter w/Bayonet for 2.4"
• STL-1071    SBIG STL Camera Adapter for 2.4"
• AD2-1110    Apogee U47-D2 Camera Adapter for 2.4"          

Focal Path: Extension

• TLF-0040    0.040" (1mm) Long Accessory Tube for 2.4"
• TLG-0080    0.080" (2mm) Long Accessory Tube for 2.4"          
• TLA-0250    0.25" (6.4mm) Long Accessory Tube for 2.4"          
• TLB-0375    0.375" (9.5mm) Long Accessory Tube for 2.4"          
• TLC-0500    0.50" (12.7mm) Long Accessory Tube for 2.4"          
• TLD-1000    1.0" (25.4mm) Long Accessory Tube for 2.4"         
• TLS-1121    Set of 2 (TLF+ TLG) Accessory Tubes for 2.4"          
• TLS-2245    Set of 6 Accessory Tubes for 2.4"                     

Mount Rings

• MRS-4011    Mt. Rng Set for 4" dia. Tube (inc. BPL-1098)     

Focuser: Digital Indicator for "is" scopes

• LMK-2404    10 Micron Indicator Kit for 2.4" focuser          
• LMF-2405    1 Micron Fine Indicator Kit for 2.4" focuser          

Focuser: Fine Focus

• FDU-2003    FocusmateDriver 6:1, Universal               
• FMU-2319    Focusmaster Computer Interface          
• RSC-2320    Indicator to computer RS232 cable 10 ft.         

Accessories (optional) - see picture above:

B. LMK-2404/LMF-2405 Digital Indicator Kits for Large Focuser
C. DSF-8002 2" Everbrite Star Diagonal
D. FDU-2003 Focusmate Driver electronic vari-speed motor control.
E. LCL-1069 Large Field Corrector for optimized edge performance on NP101is and NP127is (for big chip sizes)
F. NPR-1073 0.8X reducer
G. AFT-1105 48mm Filter adapter
H. AD2-1110 Apogee U47 D2/Yankee Robtic adpter
I. AD7-1111 Apogee U9000/U16 D7/D9 adapter
J. STL-1071 SBIG STL series adapter
K. TRG-1072 Standard T-Ring adapter
L. CWT-2070 Canon Wide T adapter
M. A2A-1107 2" Accessory adapter
N. TLX-1108 SCT Type Threaded Filter Housing adapter
O. TLA-0250 0.25" long threaded extension
P. TLB-0375 0.375" long threaded extension
Q. TLC-0500 0.500" long threaded extension
R. TLD-1000 1.000" long threaded extension
S. NPE-1118 1.5x Extender for NPis Scopes