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Lock in Perfect Spacing for Your Tele Vue Imaging System
The Tele Vue 2.4" Accessory Tube - 1.0 (25.4mm) is a precision-machined imaging accessory tube designed to establish exact back focus distances in Tele Vue's large-aperture refractor systems. This component is not a generic spacer; it is an integral part of the optical train, engineered to eliminate flexure and maintain perfect sensor alignment for imagers using NP101is and NP127is telescopes.
Rigid Construction for a Solid Imaging Train
When assembling an imaging train with a heavy camera and filter wheel, the weakest link determines the quality of your results. This accessory tube is machined from solid aluminum with a black anodized finish to provide a rigid, non-flexing extension. This structural integrity ensures your sensor remains perfectly perpendicular to the optical axis, preventing star distortion and image shift as the telescope moves across the sky.
Secure Threaded Connections for Optical Alignment
Unlike simple slip-fit or compression ring adapters, the Tele Vue accessory tube uses robust threads on both ends to create a solid, metal-to-metal connection. This threaded design is critical for maintaining the precise centering required by field flatteners and reducers. The result is an optical train that behaves as a single unit, free from the sensor tilt that can ruin an otherwise perfect exposure.
Achieving Critical Back Focus with Tele Vue Refractors
Astrophotography requires placing the camera sensor at a specific distance from the final optical element, a measurement known as back focus. The 1.0-inch (25.4mm) length of this tube is a key value for building out the correct spacing for many common camera setups when used with Tele Vue's reducers and flatteners. By combining this tube with other spacers in the 2.4" system, you can precisely hit the required distance for a flat field of sharp stars from edge to edge.
System-Specific Design and Its Trade-Offs
It is important to understand that this is a specialized component designed exclusively for the Tele Vue 2.4" imaging system. Its large diameter and proprietary threads will not connect to standard 2-inch accessories, M48, or M42 T-threads without appropriate adapters. This specificity is its strength, ensuring zero-flexure performance within the Tele Vue ecosystem, but it is a trade-off against universal compatibility.
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How do I know if I need the 1.0" extension tube for my NP127is?
You need this tube if the total back focus distance required by your reducer or flattener, minus the back focus of your camera and other accessories, leaves a gap of approximately 25.4mm. Always consult the Tele Vue back focus charts for your specific optical configuration.
Will this Tele Vue tube connect to a standard M48 adapter?
No, not directly. This tube uses Tele Vue's proprietary 2.4" threading. To connect to M48 threads, you would need an adapter like the Tele Vue RAD-1074 nosepiece followed by a standard T-ring adapter like the TRG-1072.
Can I stack multiple Tele Vue 2.4" accessory tubes?
Yes, these tubes are designed to be stacked. Their rigid, threaded construction ensures that combining multiple tubes maintains alignment and strength without introducing flexure into the imaging train.
What's the difference between this and a standard 2" extension tube?
This 2.4" tube has a larger diameter to prevent vignetting with large camera sensors and uses secure threads instead of a slip-fit barrel. A standard 2" extension tube introduces potential for slop and tilt, which this accessory is specifically designed to eliminate.
Is this tube internally baffled or blackened?
Yes, the interior of the tube features a matte black, anti-reflective finish to absorb stray light. This improves image contrast by preventing internal reflections from reaching the camera sensor.
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| Product Number |
TV-TLD-1000 |
| Accessory Format |
Tele Vue 2.4" Imaging System |
| Optical Length |
1.0" (25.4mm) |
| Connection 1 |
2.4" Female Thread |
| Connection 2 |
2.4" Male Thread |
| Material |
Black Anodized Aluminum |
| Interior |
Anti-reflective matte black |
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Tele Vue 2.4" Accessory Tube - 1.0" (25.4mm)
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Tele Vue 5-Year Limited Warranty
