Player One M48M-M48F Adapter - 17.5mm
- Adds 17.5mm of optical path length
- Connects M48x0.75 male to M48x0.75 female threads
- Standard M48 threading is compatible with 2" filters
- Machined for precise and secure connections
The Player One M48M-M48F Adapter provides exactly 17.5mm of extension, a critical component for achieving precise back focus in an astrophotography setup. This adapter uses the standard M48x0.75 thread pitch, ensuring a secure, non-vignetting connection between your camera and field flattener, reducer, or off-axis guider.
Correct spacing is non-negotiable for sharp stars edge-to-edge, and this 17.5mm extender is a fundamental tool for hitting the common 55mm back focus standard. When your camera's sensor-to-flange distance (e.g., 17.5mm on many Player One cameras) and filter wheel thickness don't add up perfectly, this adapter fills the gap precisely. The M48 (48mm) diameter provides a larger clear aperture than older T2/M42 threads, minimizing the risk of vignetting on sensors up to full-frame size.
This adapter is a precision spacer, designed to add exactly 17.5mm of length to an M48-threaded imaging train. Its primary purpose is to help you achieve the exact back focus distance required by your field flattener or focal reducer, which is often 55mm.
You need to calculate your current back focus. Add your camera's sensor-to-flange distance, the thickness of your filter wheel or drawer, and any other adapters. If this total is less than the required back focus of your flattener/reducer (e.g., 55mm), you need a spacer. This 17.5mm adapter is a common length needed to complete that distance.
Yes. The M48x0.75 thread pitch is the standard for 2" astronomy filters. This means you can thread this adapter directly onto filter cells, filter wheels, and other accessories that use the 2" filter standard, ensuring broad compatibility.
Yes, you can stack multiple M48 spacers to achieve a custom length. However, be aware that each threaded connection is a potential point for flexure or tilt. For optimal rigidity, it is always best to use a single spacer of the correct length whenever possible.
Yes, indirectly. While the adapter itself doesn't affect the image, it ensures your field flattener works correctly. Without the right spacing, like the 17.5mm this provides, you would see elongated stars in the corners of your image of M31. By correcting the spacing, this adapter enables your optics to produce sharp stars across the entire field of view.
Yes, you can use the 17.5mm adapter as part of the total 105mm distance. You would combine it with your camera, off-axis guider, and other M48 extension tubes to build up the full 105mm required by the SCT reducer for optimal performance.
| Optical Length | 17.5mm |
| Female Thread | M48 x 0.75 |
| Male Thread | M48 x 0.75 |
Player One M48M-M48F Adapter
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