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Unlock the Full Imaging Frame of Your NP Refractor
The Tele Vue Large Field Corrector (LCL-1069) is the definitive optical accessory for astrophotographers using NP101, NP101is, or NP127is telescopes who want to employ large-format camera sensors. This corrector is engineered to eliminate the final vestiges of field curvature inherent in the Petzval design, producing pinpoint stars across the entire diagonal of today's largest CCD, CMOS, and DSLR sensors.
While the native NP optical design delivers a superb flat field for smaller sensors, scaling up to full-frame (43mm diagonal) or larger formats reveals subtle star elongation at the extreme edges. The Large Field Corrector is not a generic flattener; it is a dedicated optical system designed by Tele Vue to work in harmony with the NP-series' optics, ensuring the telescope's celebrated performance extends corner to corner on your largest imaging chips.
Precision Two-Element Optical Corrector
At the heart of the LCL-1069 is a two-element, high-index glass optical system. Its sole purpose is to counteract the slight residual field curvature of the NP telescope's objective, ensuring the focal plane presented to your camera is perfectly flat. This means stars at the edge of a 50mm image circle are as round and sharp as the star dead-center.
This correction is critical when imaging wide star fields or large nebulae on a big sensor. Without it, you would be forced to crop your images to discard the soft stars in the corners, effectively wasting a significant portion of your camera's capability and your telescope's wide-field potential. The corrector ensures every pixel of your sensor is capturing data with maximum sharpness.
Full Illumination for Large Format Sensors
Optical correction is only half the battle; preventing vignetting is the other. The Large Field Corrector is mechanically and optically designed to pass the full, unobstructed light cone from the telescope's objective. This allows it to fully illuminate sensors with diagonals up to 52mm.
This avoids the dimming or "tunnel vision" effect at the corners of your images that occurs when the light path is constricted. For imagers using full-frame (24x36mm) or medium-format sensors, this means your flat frames will be easier to apply, resulting in a more uniform background and drawing more attention to the faint, extended details in your target.
The Rigid 2.4-inch Threaded Interface
To maintain perfect optical alignment, the corrector attaches directly to the NP focuser's drawtube via a large 2.4-inch thread. This rigid, direct-thread connection is a significant upgrade over compression-ring or set-screw based adapters. It completely eliminates the possibility of tilt, which is a primary cause of misshapen stars in one corner of an image.
This secure mounting ensures that the corrector, your camera, and any accessories in the imaging train are held perfectly orthogonal to the telescope's optical axis. This stability is essential during long exposures, especially on equatorial mounts where the instrument orientation changes throughout the night. It provides peace of mind that your optical train is a single, solid unit.
Achieving Critical Back Focus Spacing
This corrector's performance is entirely dependent on maintaining a precise distance between its rear flange and your camera's sensor plane. The required back focus is 84.6mm, with a tight tolerance of only +/- 1mm. This is a deliberate design trade-off; achieving perfect edge correction requires this level of precision.
Tele Vue's Imaging System accessories, such as the Canon and Nikon Wide T-Adapters and various spacer tubes, are designed to achieve this distance with specific camera models. While this requires careful planning of your imaging train, it is the key that unlocks the corrector's full performance. The result of this precision is a truly flat field that lesser, more forgiving systems cannot match.
Imaging the Cygnus Loop with a Full-Frame Sensor
Imagine framing the entirety of the Veil Nebula complex with your NP127is and a full-frame monochrome camera. Using the Large Field Corrector, the fine, thread-like filaments of NGC 6992 (the Eastern Veil) and the delicate shockwave of NGC 6960 (the Witch's Broom Nebula) are rendered with equal sharpness. The thousands of stars scattered across the field, from the brilliant 52 Cygni to the faintest background specks, remain perfect pinpoints right into the corners of the 36mm-wide frame.
Without the corrector, this same view would show those corner stars beginning to stretch, pulling your eye away from the delicate details of the nebula. The LCL-1069 makes the telescope's entire corrected image circle usable, transforming your instrument into a truly professional wide-field astrograph.
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Do I need this corrector for visual use with my NP101is or NP127is?
No, this corrector is designed exclusively for astrophotography with large sensor cameras. The native optical design of the NP-series telescopes is already exceptionally well-corrected for visual observing with all Tele Vue eyepieces.
Will the LCL-1069 work with my Tele Vue TV-85 or TV-76 telescope?
No, this corrector is specifically designed for the optical prescription and focuser of the NP101, NP101is, and NP127is models. For other Tele Vue refractors, you would use a different reducer or flattener, such as the TRF-2008 or RFL-4087.
How do I get the exact 84.6mm back focus spacing?
Tele Vue produces a system of adapters and spacers specifically for this purpose. You will need to use a combination of Tele Vue's Wide T-adapters for your specific camera brand and their 2.4-inch accessory tubes to achieve the required distance.
Does this corrector change the focal length of my telescope?
No, the Large Field Corrector is a 1.0x flattener. It does not reduce or increase the focal length or focal ratio of your telescope. Its function is purely to correct for residual field curvature.
Can I use 2-inch filters with this corrector?
Yes. You can attach a 48mm (2-inch) filter to the Tele Vue Imaging System nosepiece (RAD-1074) or use a filter slider/wheel in your imaging train, provided you can still meet the 84.6mm back focus requirement.
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| Product Code |
LCL-1069 |
| Application |
Field Flattener for Astrophotography |
| Magnification Factor |
1.0x |
| Compatible Telescopes |
Tele Vue NP101, NP101is, NP127is |
| Telescope Connection |
2.4-inch Female Thread |
| Camera Connection |
Tele Vue Imaging System Accessory Thread |
| Required Back Focus |
84.6mm ± 1mm from rear flange |
| Max Illuminated Field |
52mm diagonal |
| Weight |
0.75 lbs (340 g) |
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Large Field Corrector
× 1
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Dust Cap (Telescope Side)
× 1
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Dust Cap (Camera Side)
× 1
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Tele Vue 5-Year Limited Warranty
