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DayStar 80mm Off-Axis ERF with 311mm Inside Diameter Cap

by DayStar
SKU E-311F80
Special Order
Original price $550.00 - Original price $550.00
Original price
$550.00 - $550.00
Current price $550.00


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DayStar 80mm Off-Axis Energy Rejection Filter with 311mm Inside Diameter Cap - for 10-inch SCT - E-281F80

The DayStar 80mm Off-Axis Energy Rejection Filter, designed for 10-inch SCT telescopes, comes with a 311mm Inside Diameter Cap.

This specialized filter plays a crucial role in enhancing observations. It works by reducing the heat on your filter assembly.

It achieves this by either absorbing or reflecting UV and/or IR light, allowing only the desired visual spectrum to pass through.

Typically, these filters are made of Red or Yellow glass, or dielectric IR and UV materials.

They ensure that the light passing through falls within the visual spectrum. Additionally, the ERF can function as an aperture mask, ensuring that light approaches the filter at a straight angle.

For optimal performance, it's recommended to operate DayStar filter assemblies at f/30 or slower.

Achieving this configuration is straightforward with the appropriate ERF and/or Barlow lens. This setup ensures the best results for your observations.

 Important Instructions:

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

  • Please indicate the telescope you plan to use with this ERF and take accurate measurements of the outer diameter of the telescope's dew shield using a ruler. This precise data is crucial, as each ERF is custom made to guarantee a seamless fit.
  • In the event that this measurement is not provided, it may lead to a temporary hold on your order until the necessary information is obtained. Your satisfaction and optimal performance is our priority.


      Features & Highlights:

      • 80mm ERF Glass: Our ERF boasts an intricately crafted 80mm aperture, meticulously fine-tuned for solar observation. This size offers a harmonious blend of light-gathering capability and resolution, delivering vivid and intricate solar feature views.
      • 311mm Inside Diameter Cap: Included in the package is a 311mm inside diameter cap, ensuring a secure and snug fit with compatible telescopes. This cap plays a pivotal role in the reduction of stray light, thus facilitating precise and unobstructed solar observations.
      • SCT Compatibility: The ERF is purposefully engineered for seamless compatibility with 10-inch SCT (Schmidt-Cassegrain) telescopes. This guarantees a hassle-free integration with your current optical setup, enabling a smooth and effective solar observation experience.
      • Advanced Energy Rejection: Our ERF is designed to substantially diminish the heat load on your filter assembly. This is achieved through efficient absorption or reflection of UV and/or Infrared light, thereby enabling the transmission of light within the desired visual spectrum.
      • Multi-Coated Optics: All optical surfaces undergo precise multi-coating to augment light transmission and minimize internal reflections. This yields bright, high-contrast solar images with exceptional clarity and detail.
      • Off-Axis Design: The off-axis design offers an unobstructed view of the solar disk, maximizing the amount of light captured by your telescope. This design feature ensures that you can scrutinize the sun's features with the utmost precision.
      • Dual Functionality as an Aperture Mask: Our ERF has a dual purpose as an aperture mask, ensuring a direct angle of incidence for incoming light. This distinctive feature enhances filtering efficiency, guaranteeing the transmission of only the desired wavelengths.
      • Robust Construction: Constructed from top-quality materials, the ERF is built to withstand outdoor use, ensuring durability and longevity. It's engineered to maintain peak performance over time.
      • Recommendations for Optimal Performance: For optimal results, DayStar recommends operating filter assemblies at f/30 or slower. This configuration can be effortlessly achieved with the appropriate ERF and/or Barlow. In situations where higher resolution or larger aperture configurations are in use, the inclusion of a Barlow is advised to enhance the viewing experience.


              What's Included:

              ✓ DayStar 80mm Off-Axis ERF for 10-inch SCT

               ✓ 5 Year Warranty



              SKU E-311F80
              Block Ultraviolet Yes
              Block Infrared Yes

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