Tele Vue®

Vi s i o n a r y

WARRANTY INFORMATION

We sincerely thank you for your purchase and wish you years of pleasure using it!
Tele Vue Warranty Summary
Eyepieces, Barlows, Powermates, & Paracorr have a “Lifetime Limited” warranty, telescopes & accessories are warranted for 5 years. Electronic parts are warranted for 1 year. Warranty is against defects inmaterial or workmanship. No other warranty is expressed or implied. No returns without prior authorization. Please keep your receipts in case you need warranty service.
Lifetime Limited Warranty details online: http://bit.ly/TVOPTLIFE
5-Year/1-Year Warranty details online: http://bit.ly/TVOPTLIMITED
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Keep For Your Records
Dealer: __________________________________ City/State/Country: _________________________
Date (day/month/year): _____/_______/_______ Item Code / Description _______________________
32 Elkay Dr., Chester, New York 10918 (845) 469-4551. televue.com@televueoptics

(NPR-2073) 0.8x Reducer for NP Telescopes
Introduction
This 0.8x focal reducer was specifically designed to be used with theNP127is and NP101is. While it can also be used to enlarge the fieldof other Tele Vue Petzval type telescopes, it will not provide additionalcorrection for those models. This reducer was designed to minimize
vignetting with camera sensors up to 43mm diagonal (Full Frame) andis a replacement for the previous 0.8x reducer, the NPR-1073, which
worked best up to APS-C sensors. When combined with a Tele Vue Petzval type telescope, it reduces the focal lengthof the telescope by 20% and makes it that much faster. This increases the telescope’s field of view by 25%.
Objective SideFor Imaging System scopes, install an I.S. Imaging Adapter to the front of the reducer. If you find that the drawtube
extends more than 1.5 inches in order to reach focus, install spacers between the reducer and I.S. adapter. For use on
other Tele Vue Petzval model telescopes with 2-inch focusers, use the RAD-1074 Adapter instead of the I.S. ImagingAdapter. Note that when used with 2” focusers there will be increased vignetting for full frame sensors because of
the inner diameter of the 2-inch barrel.
Camera SideThe reducer has a nominal Back
Focal Length (BFL) of 68mm,
measured from the reducer rearshoulder as shown in figure 1. This
BFL will work best for most color
imaging applications such as OSC
and DSLR full-frame and crop sensors,and in monochrome with either LRGB
or HST palette filters (but only withcrop sensors). Imaging with DSLRs is
only possible with this BFL because
68mm is large enough to support
NPR 2073
the 55mm needed for DSLRs. For
REAR SHOULDERDSLR use, install a ¼ inch I.S. spacer(TLA-0250) and then a camera adapter suchas the CWT-2070 or NWT-2073.

figure #1

NPR-2073 FOCAL PLANE,
PLACE SENSOR HERE

figure #2TELESCOPE ORIGINALFOCAL PLANE

NPR-2073 FOCAL PLANE,
PLACE SENSOR HEREREAR SHOULDER

Vi s i o n a r y

31MM99 MM

NPR 2073

®

43MM
IMAGE
CIRCLE68 ±1 MMFILL WITH ACCESSORIES:SPACERS, ADAPTER, FILTERWHEEL,OAG, FILTER DRAWER, ETC.

In the special case of imaging in full-frame
monochrome with either LRGB or HST palettefilters, a BFL of 50mm should be used, asshown in figure 2. This BFL includes a +1mm
focus shift required for a single 3mm filter.
In this configuration, star images in isolated
wavelengths focus sharper at the very edges ofthe field than they would have in color cameras.

Tele VueTELESCOPE ORIGINALFOCAL PLANE

50 ±1 MMFILL WITH ACCESSORIES:SPACERS, ADAPTER, FILTERWHEEL,OAG, FILTER DRAWER, ETC.

43MMIMAGECIRCLE

19MM

69 MM

32 Elkay Dr., Chester, New York 10918 (845) 469-4551. televue.com@televueoptics

V03/01/23