The Player One S series filter is engineered with top-notch optical glass and utilizes multi-layer composite coating tech, delivering exceptional optical quality that's perfect for astrophotography.

What's the 2-inch ERF Filter for?

This 2-inch ERF (Energy Rejection Filter) is specifically designed as a companion for your Quark Chromosphere (H-alpha version). Its main function is to mitigate energy to help prolong the lifespan of your Quark setup. Note that this ERF filter is compatible with refractors up to 6 inches in size, and it's not intended for eyepiece-based observation.

Why Use an ERF with Your Quark?

The initial filter on a Quark is pretty small, and when you're viewing something as large as the solar disk, that filter can heat up, along with its holder. By adding this 2-inch ERF, you're safeguarding both the filter and its holder from extreme temperatures. The ERF is crafted from B270 transparent glass with a multi-coating finish, which means it'll reflect most of the energy rather than absorb it.

Any Other Applications?

Absolutely! This ERF filter is also great for lunar imaging. It provides an even brighter image compared to an IR685 filter and can even enhance image quality by improving the 'seeing' conditions.

Specifications

• Diameter: 2 inches, with M48*0.75 threading
• Frame Depth: 5mm body + 2.5mm thread, totaling 7.5mm
• Lens Thickness: 2.5mm
• Surface Quality: 1/4 lambda PV
• Bandwidth: Approximately 60nm
• Light Throughput: 97%
• Blocking Range: OD4, spanning 200nm to 1100nm

So, whether you're capturing the solar disk or the moon's craters, this ERF filter has got you covered.