DayStar Filters 75mm-Aperture Energy Rejection Filter (Specify Cap Diameter)
| Article number: | E-XN75 |
| Availability: | More on the Way to us |
| Delivery time: | Special Order |
Key Features
- For Use on Refractor and Maksutov OTAs
- Reduces Heat Load on Filter Assembly
- Absorbs or Reflects UV and/or IR Light
- For H-alpha, Sodium, Helium D3 Filters
Daystar Filters' 75mm-Aperture Energy Rejection Filter is designed for on-axis use with Refractor and Maksutov-style OTAs to reduce the heat load on your filter assembly by absorbing or reflecting UV and/or IR light while transmitting light in the desired spectrum. This ERF can be used with H-alpha, Sodium, and Helium D3 solar filters, but is incompatible with calcium wavelengths.
Choose the ERF aperture size to approximately match your refractor's objective aperture or Maksutov corrector plate. Select the correct filter cap size by measuring the outside diameter of the OTA's dew shield and choose the ERF with the smallest inside diameter that will fit over the dew shield. A set of screws is included to secure the ERF into place.