Antlia Solar Discover Dualband Energy Rejection Filter (ERF)

The Antlia Dualband Solar Energy Rejection Filter is designed by combining Hydrogen Alpha, Calcium K-Line and Calcium H-Line in one dualband filter. It is the filter used in conjunction with Antlia Solar Discover 3nm CaK, Solar, 5Å CaK or similar product to protect your solar imaging equipments from high temperature and bandpass shifting by rejecting massive heat before it enters telescope when imaging and observing solar.

They are very effective at blocking UV and IR light, and allow the desired wavelengths Ha 656.3nm, CaK 393.3nm and CaH 396.8nm to pass through.

Product Features:

- FWHM 25nm with CWL at H-alpha wavelength of 656.3nm; Transmission: T＞95%

- FHWM 25nm with CWL at CaK wavelength 393.3nm covering Calcium K-Line 393.3nm and Calcium K-Line 396.8nm; Transmission: T＞90%

- Coating Range: 200-1700nm wavelengths

- Finished with the most advanced multicoatings

- Coated on heat resistant double-polished substrate

- Antlia ERF 130mm, 150mm，200mm filters are mounted in a housing/cell to hold it in front of the telescope

- Antlia ERF 2’’ mounted filter is installed on the back end of the refractor telescope

- Transmitted Wavefront: Lambda/4 or better.

Important Notes:

- The Antlia Dual ERF filters cannot be used on its own. It must be used together with the professionally made solar imaging equipments, which have their own complete blocking filters assembled. Such as Antlia Solar Discover 5Å CaK, Solar Discover 3nm CaK Assembly, Dualband Ha, CaK and CaH filter Assembly;

- Please do not use the Antlia Dualband ERF filter by itself for visual observation;

- 2’’ ERF filter must working on 110mm or smaller refractors.