The Player One ERF S-Series 1.25″ Filter – Quark Chromosphere (SKU: ERF125 ) is a compact Energy Rejection Filter designed to work with the popular DayStar Quark Chromosphere module in small refractors (objective diameter up to ≈ 90 mm). The filter is placed in the 1.25″ attachment in front of the etalon and effectively blocks radiation outside the H-α band, reducing the amount of thermal energy and protecting the Quark Barlow shoe from overheating. At the same time, it provides over 90% transmission in the 654–658 nm window, guaranteeing maximum contrast of prominences and chromosphere details.
• Diameter 1.25″ (M28.5 × 0.6) – fits directly into the Quark eyepiece sleeve
• high transmission in H-α 656 nm (> 90 %)
• effective UV/IR suppression < 0.1% – standard and matrix protection
• multi-layer, hardened dielectric coatings – scratch and moisture resistance
• λ/4 optical glass, parallel ≤ 30″ – no influence on the system aberration
• thin aluminum frame (ring thickness 5 mm) with blackened edges
• Diameter/housing: 1.25″ – thread M28.5 × 0.6
• clear diameter: 23 mm
• substrate: optical glass, thickness 2 mm
• transmission range (T > 90%): 654–658 nm
• UV/IR attenuation: < 0.1% @ ≤ 400 nm & ≥ 700 nm
• coatings: dielectric, double-sided, hard-coated
• max. recommended telescope lens diameter: 90 mm
• weight: 10 g
By using the ERF 1.25″ S-Series with Quark, you gain more stable standard operation, shorter warm-up time and less risk of temperature drift during long H-α sessions. It is a compact, lightweight and yet effective protection for small solar refractors.
