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DayStar 100mm ERF with 140mm Inside Diameter Cap

by DayStar
SKU E-140N100
Original price $695.00 - Original price $695.00
Original price
$695.00 - $695.00
Current price $695.00
In stock

Ships To: United States & Canada 🇺🇸 🇨🇦

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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 100mm Energy Rejection Filter with 140mm Inside Diameter Cap - For Refractor - E-140N100

The DayStar 100mm Energy Rejection Filter featuring a 140mm Inside Diameter Cap, specifically designed for refractor telescopes.

These cutting-edge filters are meticulously crafted to greatly diminish the thermal stress on your filter system.

This is accomplished through the efficient absorption or reflection of UV and/or I light, allowing seamless transmission of light within the desired visual spectrum.

You can choose from variants in either Red or Yellow glass, or opt for filters made from high-quality dielectric IR and UV materials.

These filters guarantee precise filtration while allowing the passage of desired wavelengths.

Notably, the ERF also functions as an aperture mask, ensuring a direct angle of incidence for incoming light, thereby boosting filtering efficiency.

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

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

In cases of higher resolution or larger aperture setups, incorporating a Barlow is advised 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 identify the telescope that will be paired with this ERF (Energy Rejection Filter) and take precise measurements of the outer diameter of the telescope's dew shield at the front, using a ruler. This accurate measurement is essential because our ERFs are custom made to guarantee a perfect fit.
  • If you fail to provide this measurement, it may lead to a temporary delay in processing your order until we obtain the required information. Your satisfaction and optimal performance is our priority.


Features & Highlights:

  • 100mm Energy Rejection Filter (ERF) Glass: is an intricately designed optical component crafted with meticulous attention to detail. It is specifically engineered to effectively mitigate thermal influences on your filter assembly. Through expert absorption or reflection of UV and IR light, it selectively permits only the desired visual spectrum to pass through. This deliberate filtration technique ensures a consistently crisp viewing experience, reducing any possible disturbances arising from thermal effects.

  • Heat Management Excellence: The DayStar Energy Rejection Filters are masterfully crafted to relieve your filter assembly from excessive heat. Through adept absorption or reflection of UV and/or IR light, they exclusively permit light within the desired visual spectrum. This safeguard ensures a reliable and unwavering performance by protecting the telescope's vital optical components.
  • Diverse Material Options: Catering to specific observational requirements, these filters offer an array of materials. Choose from Red or Yellow glass, or opt for dielectric coatings. Each option excels at obstructing unwanted UV and IR wavelengths, providing versatility aligned with your precise goals.
  • Visual Spectrum Brilliance: While proficiently screening out UV and IR, these filters shine in transmitting light within the desired visual spectrum. This commitment to clarity guarantees observations and images captured with these filters are characterized by precision, freedom from distortions, and unmatched clarity.
  • Dual Functionality as Aperture Mask: Serving as both an Energy Rejection Filter (ERF) and an aperture mask, it ensures that incoming light meets the telescope's optics at an ideal and direct angle. This dual role significantly amplifies the quality and precision of your observations.
  • Ideal Operational Settings: DayStar filter assemblies achieve their zenith performance at f/30 and slower settings. This optimal configuration is easily attained with the inclusion of the appropriate ERF and Barlow, securing perfect alignment within your telescope's optical system.
  • Tailored Compatibility: Streamline your selection process with DayStar's comprehensive list of compatible reflectors and refractors. If you have a specific telescope model in mind, their seasoned team stands ready to guide you towards the perfect filter for your equipment.
  • Exacting Precision in Machining: ERFs undergo meticulous custom machining, underscoring an unwavering dedication to detail and precision in the manufacturing process. This ensures the filter is flawlessly tailored to meet the unique requirements of your telescope, guaranteeing a seamless and accurate fit.
  • Critical Measurement Requirement: To expedite the customization process, DayStar courteously requests an accurate measurement of the outermost (largest) diameter of your telescope's dew shield at the foremost end. This level of precision is pivotal in securing an impeccable fit and optimal performance of your ERF. Rest assured, your satisfaction and superior viewing experience remain their foremost priorities.
  • Durable and Protective Construction: The ERF is securely housed in a robust cell with a 140mm ID cap, providing an extra layer of protection to safeguard the filter when not in use. This construction ensures the filter's longevity and continued high performance.


    What's Included:

    ✓ DayStar 100mm ERF with 140 ID Cap

    ✓ 5 Year Warranty



    SKU E-140N100
    Block Ultraviolet Yes
    Block Infrared Yes


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