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DayStar 63mm Off-Axis ERF with 244mm Inside Diameter Cap

by DayStar
SKU E-244F63
Special Order
Original price $550.00 - Original price $550.00
Original price
$550.00 - $550.00
Current price $550.00


Ships To: United States & Canada 🇺🇸 🇨🇦

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We offer a 30 Day Return Policy on most of the products that we carry.

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The vast majority of products that we sell, with a few exceptions, are covered under Warranty.

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DayStar 63mm Off-Axis Energy Rejection Filter with 244mm Inside Diameter Cap - for 8-inch SCT - E-244F63

Introducing the DayStar 63mm Off-Axis Energy Rejection Filter with 244mm Inside Diameter Cap for 8-inch SCT telescopes:

These specialized Energy Rejection Filters effectively alleviate thermal strain on your filter assembly.

They achieve this by absorbing or reflecting UV and/or Infrared light while seamlessly transmitting light within the desired visual spectrum.

These filters are available in either Red or Yellow glass variants, or utilize high-quality dielectric materials for IR and UV filtration, ensuring precise light transmission within the desired visual spectrum.

Moreover, the ERF also functions as an aperture mask, guaranteeing a direct angle of incidence for incoming light, further enhancing its filtering efficiency.

For optimal performance, DayStar recommends operating filter assemblies at f/30 or slower.

Achieving this f/30 configuration is effortlessly accomplished with the appropriate ERF and/or Barlow lens.

 Important Instructions:

To facilitate a seamless integration, after your order is placed, please reach out to us via email with the following details:

  • Please specify the telescope intended for use with this ERF and meticulously measure the outer diameter of the telescope's dew shield at the front using a ruler. This precise measurement is paramount, as ERFs are custom made on an individual basis to ensure a perfect fit.
  • Failure to provide this measurement may result in a temporary hold on your order until the necessary information is retrieved. Your satisfaction and optimal performance is our priority.


Features & Highlights:

  • 63mm ERF Glass: The ERF features a precisely crafted 63mm aperture, optimized for solar observation. This size strikes a balance between light-gathering ability and resolution, providing clear and detailed views of solar features.
  • 244mm Inside Diameter Cap: The included 244mm inside diameter cap ensures a secure and snug fit with compatible telescopes. This cap plays a vital role in minimizing stray light, allowing for precise and unobstructed solar observations.
  • SCT Compatibility: The ERF is specifically engineered for compatibility with 8-inch SCT (Schmidt-Cassegrain) telescopes. This ensures seamless integration with your existing optical setup, allowing for a hassle-free and effective solar observation experience.
  • Advanced Energy Rejection: The ERF is designed to significantly reduce the heat load on your filter assembly. This is achieved through the efficient absorption or reflection of UV and/or Infrared light, enabling the transmission of light within the desired visual spectrum.
  • Multi-Coated Optics: All optical surfaces are precision multi-coated to enhance light transmission and reduce internal reflections. This results in bright, high-contrast solar images with exceptional clarity and detail.
  • Off-Axis Design: The off-axis design allows for an unobstructed view of the solar disk, maximizing the amount of light collected by the telescope. This design feature ensures that you can observe the sun's features with utmost precision.
  • Dual Functionality as an Aperture Mask: The ERF serves a dual purpose as an aperture mask, guaranteeing a direct angle of incidence for incoming light. This unique feature enhances filtering efficiency, ensuring that only the desired wavelengths are transmitted.
  • Robust Construction: The ERF is constructed from high-quality materials, ensuring durability and longevity. It is designed to withstand the rigors of outdoor use and maintain peak performance over time.
  • Recommendations for Optimal Performance: For the best results, DayStar recommends operating filter assemblies at f/30 or slower. This configuration is effortlessly attained with the right ERF and/or Barlow. In instances of higher resolution or larger aperture configurations, the inclusion of a Barlow is advised for an enhanced viewing experience.


      What's Included:

      ✓ DayStar 63mm Off-Axis ERF for 8-inch SCT

       ✓ 5 Year Warranty



      SKU E-244F63
      Block Ultraviolet Yes
      Block Infrared Yes

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