Altair Astro 160mm TRIBAND D-ERF Solar Energy Rejection Filter (Hydrogen Alpha plus CaK CaH)

Altair Astro 160mm TRIBAND D-ERF Solar Energy Rejection Filter

• Advanced Solar Protection: Designed to protect telescopes and solar imaging equipment from excessive heat build-up, specifically when using Daystar Hydrogen Alpha Quark or similar Hydrogen Alpha Etalon filters.
• Specialized Coatings: Features special coatings that block Infrared and Ultraviolet light, along with most unwanted solar emission spectra, transmitting only Hydrogen Alpha and Calcium K-Line and H-Line wavelengths.
• Narrow Bandpass Precision: Offers a 40nm FWHM bandpass for enhanced contrast and effective blocking, ensuring high-quality solar imaging.
• Essential for Safe Solar Imaging: Must be used in conjunction with a professional Etalon product like the Daystar Quark, which includes complete blocking filters at the eyepiece end of the telescope, to prevent serious eye damage.
• Heat Reduction: Reduces approximately 98% of heat reaching the optics, preventing the Etalon from drifting off-band and protecting equipment.
• Dual Calcium and Hydrogen Alpha Transmission: Delivers 40nm FWHM bandpass at both H-alpha and Calcium wavelengths, with high transmission rates (~95.5% for H-alpha and ~85% for Calcium).
• UVIR Blocking: Offers OD3 0.1% @400-1100nm blocking, reducing over 98% of heat towards the 3rd party Etalon.
• Large Diameter: The filter measures 160mm in diameter with a thickness of 12.0mm, required to achieve flatness and maintain optical quality.
• Durable Multilayer Coatings: Protected by SiO2 hard overcoat, ensuring durability and performance.
• Optional ERF Cell / Housing: While the ERF filter element comes without a housing, an optional cell can be ordered for ease of installation.
• Compatibility and Usage: Ideal for use with 3rd party Etalon filters for solar imaging, not intended for standalone use.
• Cleaning and Maintenance: Includes guidelines for safe and effective cleaning, ensuring long-term performance without damaging the coatings.
• Safety and Quality: Emphasizes the importance of using the filter in conjunction with proper solar filtration products to ensure safe observation and imaging.