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)
Why add a ERF on Quark?
First filter on Quark is quite small, the solar disk might bigger than it, the light will heat the filter and it’s holder. With this 1.25″ ERF filter, we can protect both the filter and filter holder from high temperature.
And don’t worry about the ERF itself, it’s use B270 transparent glass and multi coating, it will reflect not absort most energy.
Does it has any other usage?
Yes, this ERF filter also can be used in Lunar imaging, it will provide even brighter image than IR685 filter, also could improving the seeing.
Specifications: 1.25 inch, thread M28.5*0.6
Frame thickness: body 5mm+ thread 2mm, a total of 7mm
Thickness of filter lens: 2mm
PV: 1/4 lambda
Blocking depth: OD2 (300nm-1100nm)
A Knox –
Great value solution for small aperture refractors. Saves having to invest in a full front objective ERF with holder. (Used with my Quark Combo and separate telecentric Barlow.)