IMPORTANT SAFETY INFORMATION: DO NOT USE THIS FILTER FOR DIRECT SOLAR OBSERVATION! Must be used together with a professional solar filter film or glass type, or Hershel Wedge with Max. 0.024% transmission placed BEFORE this filter. For reflecting telescopes, we recommend installing a solar film filter on the front of the telescope, then screwing the filter into a filter holder, camera, or eyepiece. For refractors, the G-Band filter should be positioned just in front of the camera or eyepiece with a Hershel Wedge in place ahead of it. Do not use this filter without a suitable solar pre-filter in place, because it will permanently damage your eyes or camera! 

Do not insert the filter before your Hershel Prism or it will melt, it should be placed just in front of the camera, AFTER THE HERSCHEL PRISM. For a Hypercam you can use an Altair Magnetic Filter holder with 2" filter slider.

Altair 2nm G-Band Solar Contrast Filter - 2" 430.3nm: Enhancing Solar Imaging

• Innovative Solar Astronomy Tool: The Altair G-Band 2nm Solar Filter is a pioneering accessory for solar astronomy, specifically designed to accentuate finer details in the solar photosphere.
• Enhanced Contrast and Detail: This filter significantly boosts contrast, making features such as faculae, sunspots, umbral and penumbral areas more distinct. It also amplifies the visibility of granulation in the photosphere.
• Revealing Unique Solar Features: Ideal for advanced solar imagers, the G-Band filter can potentially expose "bright spots" between solar convection cells, especially when used with reflectors of 250mm aperture or larger.
• Compatibility and Usage: Perfect for all-mirror, open-tube designs like Newtonian telescopes and Classical Cassegrains. Essential to pair with Baader "imaging" ND3.8 solar film for optimal performance.
• Safety Compliance: Must be used in conjunction with a professional solar filter, such as Baader Solar Film Filters or a Herschel Wedge. Ensures the safety of both the user and equipment.
• High Transmission and Blocking: Blocks UV, IR, and visual wavelengths, transmitting only a 2nm FWHM blue band at 430.3nm, resulting in high contrast solar features. Approximately 96% transmission ensures clarity and detail.
• Recommended Camera Pairing: Best used with a monochrome camera, like the Altair Hypercam 174M or Altair GPCAM3 287M Mono USB3 Camera, for superior imaging results.
• Installation Guidance: Careful installation is advised. For refracting telescopes, position the filter before the camera or eyepiece, following a Herschel Wedge.
• Quality Assurance: Each filter comes with a unique high-resolution spectrographic analysis, specific to its serial number.
• Product Specifications: Features a standard 2" threaded aluminium cell, CWL of 430.3nm at 96% transmission, FWHM of 2nm, and OD of 6.5. The filter is 1.85mm thick with quartz λ/4, parallelism of 30 arcsec, and Si02 hard overcoat with UVIR Block.

Disclaimer:Always prioritize safety by using this filter in conjunction with appropriate solar pre-filters.

Specifications

• Standard 2" Filter Threaded Aluminium Cell
• CWL 430.3nm @ 96% transmission, tolerance 1%
• FWHM 2nm, tolerance 0.5nm.
• OD 6.5 Average blocking over 200-1100nm range. IR Blocked to 1100nm.
• 1.85mm thick quartz λ/4, Parallelism (arcsec) 30"
• Si02 "hard" overcoat with UVIR Block 300-1100nm and Anti-Reflection Coating
• High resolution spectrographic test report included corresponding to each individual filter.