ERF 1.25"

Player One S series filter using high quality optical glass substrate and multi-layer composite coating technology, which has excellent optical performance in astrophotography. 1.25inch ERF filter ( Energy rejection filter for Quark Chromosphere） This filter is an assistant filter, design for Quark Chromosphere (Ha verstion) , intend to reject energy and extend life time of your Quark. 1.25″ ERF filter must working on 5″ or smaller refractors. (DO NOT use it on eyepiece for observing)

Specifications: 1.25 inch, thread M28.5*0.6

Frame thickness: body 5mm+ thread 2.5mm, a total of 7.5mm

Thickness of filter lens: 2.5mm

PV: 1/4 lambda

Transmittance: ≈97%

Blocking depth: OD4 (200nm-1100nm)