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DayStar 130mm ERF with 180mm Inside Diameter Cap

by DayStar
SKU E-180N130
Special Order
Original price $995.00 - Original price $995.00
Original price
$995.00 - $995.00
Current price $995.00

Lead-time: 2-4 weeks

Ships To: United States & Canada 🇺🇸 🇨🇦

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We offer free U.S. shipping to the lower 48 States - on most orders over $150 USD. Some limitations may apply.

Shipping fees will apply on most orders shipping across Canada, with some exceptions.

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

For full details on our Shipping & Returns Policy, please click here.


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

To view the Warranty details for each brand that we sell, including products that do not qualify for Warranty, please visit here.

DayStar 130mm Energy Rejection Filter with 180mm Inside Diameter Cap - For Refractor - E-180N130

The DayStar 130mm Energy Rejection Filter featuring a 180mm Inside Diameter Cap, specially designed for refractor telescopes.

These cutting-edge filters have been meticulously crafted to substantially alleviate the thermal stress on your filter setup.

By proficiently absorbing or deflecting UV and/or I light, they seamlessly transmit light within the desired visual range.

You can choose from options of Red or Yellow glass, or opt for dielectric IR and UV materials, ensuring precise filtration while allowing passage of desired wavelengths.

It's worth noting that the ERF also functions as an aperture mask, guaranteeing a direct angle of incidence for incoming light, thereby heightening filtering efficiency.

For optimal results, DayStar recommends using filter assemblies at f/30 or slower.

Achieving this setup is easily accomplished with the appropriate ERF and/or Barlow.

In cases of higher resolution or larger aperture configurations, incorporating a Barlow is recommended for an even more enhanced viewing experience.

Important Instructions:

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

  • Please select the appropriate telescope for use with this ERF and carefully gauge the outer diameter of the telescope's dew shield at the front using a ruler. This accurate measurement is crucial, as ERFs are crafted to order, tailored to fit each telescope perfectly.
  • If this measurement is not provided, it may lead to a temporary delay in processing your order until the required information is obtained. Your satisfaction and optimal performance is our priority.


Features & Highlights:

  • 130mm Energy Rejection Filter (ERF) Glass: A precision-engineered optical element meticulously fashioned to effectively mitigate thermal influences on your filter assembly. Its expertise lies in adeptly absorbing or reflecting UV and IR light, permitting only the targeted visual spectrum to traverse. This strategic filtration method ensures an unwaveringly lucid viewing experience, effectively reducing any potential disturbances arising from thermal effects.

  • Advanced Thermal Management: The DayStar Energy Rejection Filters are expertly engineered to alleviate heat strain on your filter assembly. Through proficient absorption or reflection of UV and/or IR light, they ensure the smooth transmission of light within the desired visual spectrum, enhancing the viewing experience.
  • Customizable Filtration Options: These filters offer a range of material choices, including Red or Yellow glass, and dielectric coatings. Each option excels at precise filtration, guaranteeing an optimal viewing experience free from unwanted wavelengths.
  • Enhanced Optics with Aperture Mask Functionality: The ERF serves a dual role, not only as a filter but also as an aperture mask. This ensures that incoming light strikes the telescope's optics at a direct and optimal angle, significantly enhancing the quality of observations.
  • Optimal Performance Configuration: DayStar recommends operating filter assemblies at f/30 or slower for peak performance. Achieving this setup is made simple with the appropriate ERF and/or barlow, ensuring perfect alignment within your telescope's optical system.
  • Comprehensive Compatibility and Personalized Support: DayStar provides a comprehensive list of compatible reflectors and refractors for easy selection. If you have a specific telescope model in mind, their knowledgeable team is readily available to guide you towards the perfect filter for your equipment.
  • Critical Measurement Accuracy Requirement: To expedite customization, it is crucial to specify the telescope model and provide an accurate measurement (using a ruler) of the outer (largest) diameter of your telescope's dew shield at the front. This precision is paramount, as each ERF is individually machined to ensure seamless integration with your telescope.
  • Durable and Protective Construction: The ERF comes encased in a robust cell with a 180mm ID cap. This cap provides an extra layer of protection, safeguarding the filter when not in use, ensuring longevity and continued high performance.


              What's Included:

              ✓ DayStar 130mm ERF with 180mm ID Cap

              ✓ 5 Year Warranty



              SKU E-180N130
              Block Ultraviolet Yes
              Block Infrared Yes


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