ToupTek 1.25-Inch Astronomical SHO Narrowband Filters Ha+SII+OIII 6.5nm FWHM Filters for Deep Sky Photography

Introduction:
- Narrowband filters for astrophotography isolate specific emission wavelengths while suppressing unwanted background light, helping improve contrast and signal-to-noise ratio when imaging emission nebulae.
- ToupTek Astro SHO narrowband filters are precisely tuned to the three main ionized emission lines found in star-forming regions:
  Hα (656.3nm)
  SII (671.6nm)
  OIII (500.7nm)
- By using these filters, you can effectively block urban light pollution and background stray light, dramatically enhance signal contrast, and bring out incredible detail -- empowering you to achieve Hubble-like color mixing (SHO synthesis) in your astrophotography.

Specifications:
- Size: 1.25”
- Glass thickness: 2mm
- Transmission range:
  H-alpha filter: central wavelength 656.3nm
  SII filter: central wavelength 671.6nm
  OIII filter: central wavelength 500.7nm
- Transmittance: >90%
- FWHM: H-alpha (6.5nm) / SII (6.5nm) / OIII (6.5nm)
- Glass material: Quartz glass
- Frame material: Aluminum Alloy
- Surface treatment: double-sided high-precision optical polishing
- Coating technology: IAD (Ion Assisted Deposition)
- Coating system design: AR anti-reflection coating + quartz glass + precision cutoff coating layer
- OD: ≥5.0

Package Included:
- 1 x Set of SHO Filter