ERF & Solar Holders

🛡️ Solar Filters & Accessories — Safety and Reliability

Explore our range of solar holders and accessories, specially designed to ensure safe and accurate solar observation. From glass ERF filters (Baader, Lunt, Altair) to Astrosolar films for white light, Quark filter adapters, and solar finders — every part is 3D-printed in premium European white PETG for strength, reliability, and durability.

🔧 Optimized & Custom Holders

• 🧢 External protective cap included with every holder (filter longevity). Optional internal cap available to secure both sides.
• 🔩 Adapted clamping:
  • Astrosolar → 100% nylon thumbscrews (safe, lightweight, no tube marking).
  • Glass ERF → stainless steel thumbscrews with nylon tip (secure hold, tube preserved).
• 🧿 Interchangeable ERF cells: a single filter can be used on several instruments thanks to dedicated plates. Switch instruments in minutes without handling the filter — ideal given the high cost of ERFs.
• 🧰 Custom compatibility: 3D-printed rings and spacers for clean, stable, and precise mounting.

☀️ Hα & White Light: Two Complementary Approaches

• Hydrogen-alpha (Hα): imaging prominences, eruptions, and chromospheric details (ERF holders, Quark adapters, etc.).
• White light: surface observation and sunspot imaging (Astrosolar film holders and dedicated options).

Important: we mainly provide 3D-printed holders. The filters themselves are not sold here (except optional Baader Astrosolar film on certain holders).

Note: Sol’Ex / Star’Ex users generally do not need ERF or Astrosolar filters. For ND filter holders recommended by Christian Buil, please see the “Sol’Ex Accessories” category.