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Capture Wider Fields with Your Tele Vue Imaging System
The Tele Vue NPR-2073 0.8x Reducer is an essential imaging accessory designed specifically for Tele Vue NP101is and NP127is telescopes. This focal reducer shortens the effective focal length of your Petzval astrograph by 20%, creating a faster, wider photographic system without compromising the flat-field performance that defines these instruments.
A Faster, Wider Optical System
By shortening your telescope's focal length, this 0.8x reducer provides a 25% wider field of view. This allows you to frame larger deep-sky objects, like the full expanse of the Andromeda Galaxy or the intricate nebulosity of the Veil Nebula complex, within a single shot. The reduction also creates a faster photographic system, dropping an f/5.4 NP101is to f/4.3, which reduces required exposure times by about 36% to achieve the same image brightness.
Matched to the NP Telescopes
This is not a simple generic reducer. Tele Vue designed the NPR-2073 specifically for the NP127is and NP101is, to minimize vignetting with camera sensors up to 43mm diagonal (full frame). It replaces the earlier NPR-1073, which worked best up to APS-C sensors. On other Tele Vue Petzval telescopes it still enlarges the field but provides no additional correction.
Fully Multi-Coated Optics for Maximum Contrast
Each air-to-glass surface in the reducer features broadcast-quality multi-coatings to maximize light transmission and suppress reflections. This is critical when imaging faint objects, as it ensures that subtle details in nebulosity and faint galactic arms are not lost to scatter or ghosting. The high throughput delivers brighter images with a dark, high-contrast background, allowing the true structure of your target to stand out.
Secure 2.4-inch Focuser Interface
The reducer connects to the NP101is or NP127is through the threaded Imaging System parts; on NP scopes with a 2" focuser it needs the RAD-1074 adapter. This large-format connection guarantees a rigid, flex-free fit and prevents any vignetting that could occur with smaller 2-inch accessories. The secure attachment ensures your entire imaging train remains perfectly aligned, a critical factor for achieving sharp images over long exposures.
Precision Back Focus for Optimal Performance
To achieve the designed flat field, this reducer requires a back focus of 68mm (±1mm) from its rear shoulder to your camera sensor, or 50mm (±1mm) for full-frame monochrome imaging with LRGB or HST filters. This spacing is a critical specification, not a guideline. Tele Vue offers a range of precisely machined wide T-adapters and extension tubes that make achieving this distance straightforward for most popular DSLR, mirrorless, and dedicated astronomy cameras. Getting the spacing right is the key to unlocking the reducer's full performance potential.
Imaging with the 0.8x Reducer
With the reducer installed on an NP127is, turning the telescope towards the Cygnus Loop reveals its true power. The faster f/4.2 system allows you to gather significant signal on the delicate filaments of the Eastern and Western Veil in shorter sub-exposures. The wider field frames the entire supernova remnant, capturing Pickering's Triangle and the surrounding star clouds in one cohesive, sharp, and brilliantly contrasted image that a longer focal length would struggle to contain.
A Note on Compatibility
It is important to understand that Tele Vue designed this reducer specifically for the NP127is and NP101is. It can also enlarge the field of other Tele Vue Petzval-type telescopes (with the RAD-1074 adapter on 2" focusers), but it will not provide additional correction for those models. This specificity is its strength, as it guarantees diffraction-limited performance within its designated system, but it also defines its primary limitation.
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Will this reducer work with my Tele Vue TV-85 or TV-76?
No, this reducer is specifically designed for the Petzval optics of the NP101is and NP127is telescopes. For the TV-85 or TV-76, use the TRF-2008 0.8x Reducer/Flattener; for the TV-102, use the RFL-4087.
How do I get the correct 68mm back focus for my camera?
For a DSLR, install a 1/4" Imaging System spacer (TLA-0250) and then a camera adapter such as the CWT-2070 (Canon) or NWT-2073 (Nikon). For other cameras, you may need a combination of standard adapters and spacers.
Does the reducer change my telescope's focal length for visual use?
This is a photographic-only accessory. It is not designed to be used with eyepieces for visual observation and will not come to focus correctly with a diagonal in the optical train.
What is the difference between this and the TRF-2008 reducer?
The NPR-2073 is a pure reducer for the already flat-field NP scopes. The TRF-2008 is a reducer and flattener, designed to both reduce the focal length and correct field curvature in Tele Vue's doublet refractors.
Will this reducer cover a full-frame (24x36mm) sensor?
Yes, the reducer is designed to provide a fully illuminated and corrected field for sensors up to 43mm in diagonal (standard full-frame size) when used with an NP101is or NP127is telescope.
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| Product Code |
NPR-2073 |
| Focal Length Reduction |
0.8x |
| Telescope Compatibility |
Tele Vue NP101is, NP127is |
| Telescope Side Connection |
Tele Vue 2.4" Imaging System thread (RAD-1074 for 2" focusers) |
| Camera Side Connection |
Thread for Tele Vue Imaging System Adapters |
| Required Back Focus |
68mm ± 1mm (50mm ± 1mm for full-frame monochrome with LRGB or HST filters) |
| Image Circle |
43mm |
| Magnification Factor |
0.8x |
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0.8x Reducer for NP Scopes
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Tele Vue 5-Year Limited Warranty
