ANTLIA ERF Dual Band High Transmittance Astronomical Filter 25nm FWHM Ha&CaK/CaH Solar Filter M48*0.75

Introduction:
- Adopting the latest process design with high transmittance, high cutoff, and flat top optimization, as well as advanced coating technology to ensure the accuracy of its wavelength.
  T>95% at H-AIpha, FWHM 25nm
  T>90% at CaK & CaH, FWHM 25nm
- Blocking (200-1700nm): Ultra far design for UVIR cutoff. Due to the strong solar energy, the coating range is wider, from 200-1700nm, which blocks more of the solar energy in the infrared band. The out of band blocking design of OD4 (0.01%) at 300-1200nm is designed for safety considerations.
- 1/4 Lambda quartz substrate production: The filter uses a quartz substrate processed by secondary double-sided precision polishing. The 1/4 Lambda waveform has better thermal stability, lower glass expansion coefficient, and denser film layer, which is less susceptible to environmental influences and has a longer service life. The 1/4 Lambda waveform ensures that the impact of surface shape on image quality and wavelength on the image is minimized when paired with professional solar observation equipment.

Package Included:
- 1 x Filter