Chroma R-Bessell photometric filter - 2″ Mounted

Photometric Chroma R-Bessell filter

Visit Chroma R-Bessell photometric filter is designed to capture the red spectral band (approx. 550-800 nm) for precise photometric studies. It is an integral part of the UBVRI system, widely used in scientific astrophotometry to measure the brightness and colors of stars, galaxies and other celestial objects. This filter guarantees reliable performance and results comparable with historical databases, while being optimized for modern CCD and CMOS sensors.

Key features

• Spectral transmission:
  • Focused on the red (R) band, with high transmission in the 550-800 nm range.
  • Effective blocking of unwanted UV and IR wavelengths.
• Sustainable construction:
  • Multi-layer anti-reflective coatings to minimize halos and stray reflections.
  • Blackened edges to prevent internal reflections and ensure clean transmission.
  • Standard 2 mm thickness, compatible with most filter wheels and optical systems.
• Compatibility:
  • Parfocal with Chroma's other UBVRI filters (U, B, V, I), eliminating the need for refocusing.
  • Works perfectly with modern CCD and CMOS cameras, even on high-speed telescopes.

Bessell filter technology and application

Bessell filters have been a standard in astronomical photometry since they were adapted in the 1990s for modern CCD sensors. They faithfully reproduce the characteristics of the original Johnson-Cousins filters, while using advanced dielectric coatings that offer stable transmission and excellent durability.

The filter R-Bessell is essential for capturing red light, often emitted by red giant stars or nebulae rich in ionized hydrogen. It enables precise measurement of magnitude in this band, and calculation of color indices such as g'-r'. These data are crucial for characterizing temperatures, chemical compositions or stellar ages, as well as for analyzing the physical properties of galaxies.

Applications

• Scientific photometry (UBVRI):
  • Precise measurement of brightness in the red band.
  • Study of variable stars, supernovae, star clusters and galaxies.
• Advanced astrophotography:
  • The perfect complement to other UBVRI filters for producing scientifically calibrated data sets.
• Astronomical research:
  • Spectral analysis and in-depth study of the physical properties of celestial objects.

Conclusion

Visit Chroma R-Bessell photometric filter is an indispensable tool for amateur or professional astronomers wishing to carry out precise photometric studies in the red band of the visible spectrum. Its robust design, optimized transmission and rigorous calibration make it an essential choice for scientific imaging and advanced astronomical observation.