Astrophotography accessory that removes spacing headaches and reduces street light reflections, the RASTKY M48 Extension Tube Kit brings precise M48-threaded spacing control to telescope camera chains. Cleaner frames and fewer stray highlights make long imaging sessions more satisfying. Is a manual ring set the right way to tighten up your focus and framing?
⚡ At a Glance
- • Image Quality: Minimises light and street reflections to help capture clearer astrophotography frames
- • Best for: Astrophotographers with M48-threaded eyepiece holders needing accurate spacing
- • Not ideal for: Setups that use non-M48 thread standards or require motorised focusing systems
Eight anodised aluminium M48 extension rings enable flexible spacing combinations for telescope cameras. Precision mating threads ensure repeatable alignment between eyepieces and adapters.
Precise backfocus control - With eight M48 extension rings
A set of eight individual rings threads together using the M48 x 0.75 standard, allowing many stack combinations to reach exact spacing needs. Threaded joins ensure alignment while changing the optical path length.
Fine adjustments to imaging distance become straightforward, making it easier to reach camera sensor focus without resorting to bulky adapters. Frequent reconfiguration for different cameras or reducers can be achieved without guessing spacings.
Cleaner frames in urban skies - Thanks to spacing that reduces stray light
Spacing choices place the camera sensor at optimal distance from focal planes and accessories, reducing internal reflections and minimising pick-up of nearby street illuminations. The all-metal tube walls limit light scatter compared with cheaper plastic alternatives.
Sky contrast improves when stray light is reduced, so nebulae and faint stars appear with better definition. Short exposures in light-polluted locations benefit from fewer flare artefacts.
Long-lasting mechanical reliability - With anodised aluminium construction
Fully metal construction uses anodised aluminium for each extension ring, providing corrosion resistance and a durable mating surface for repeated assembly. Threads are finished to give smooth engagement and consistent torque.
Rugged hardware stands up to frequent field use and repeated wardrobe of rings, keeping alignment stable across sessions. A neat finish also aids clean stacking and reduces the chance of seized threads.
✨ The 4 Key Reasons for RASTKY M48 Extension Tube Kit
- M48 x 0.75 thread standard - Fits common M48 eyepiece holders and camera adapters reliably
- Eight ring sizes - Offers flexible spacing to achieve accurate backfocus combinations
- Anodised aluminium build - Durable finish resists wear, protecting thread engagement
- Precision mating threads - Smooth joins deliver repeatable alignment for imaging setups
📋 Technical Details at a Glance
- Category: Astrophotography extension tube kit
- Brand: RASTKY
- Thread: M48 x 0.75
- Pieces included: 8 extension rings
- Material: Anodised aluminium
❓ Frequently Asked Questions
Q: Are these rings compatible with my telescope?
A: Compatibility requires M48-threaded eyepiece holders or adapters, since the kit uses the M48 x 0.75 standard.
Q: Do the rings help reduce street light reflections?
A: Stacking rings to achieve correct spacing helps minimise internal reflections and reduce the impact of nearby street lights, improving image clarity.
Q: What material are the rings made from?
A: Each extension ring is fully metal with an anodised aluminium finish for durability and consistent thread mating.
🏆 Our Verdict
Well suited to amateur and dedicated astrophotographers who use M48-threaded eyepiece holders and need precise, repeatable spacing. Adjustable combinations of eight anodised aluminium rings reduce stray light and give reliable mechanical alignment. While a manual ring set cannot replace motorised focussing, the durable design should deliver long-term value for imaging rigs that need accurate backfocus control.
