Optolong H-alpha Filter 3nm 2 inch

Optolong Filters H-alpha 3nm 2″ is a professional narrowband filter that passes only the H-alpha emission line (656.3 nm) with an extremely narrow bandwidth of 3 nm. This captures hydrogen-rich nebulae such as the Rosette Nebula, the North American Nebula and the Orion Nebula with exceptional detail and contrast.

Thanks to its ultra-slim pass-through, the filter effectively blocks virtually all other light, including disturbing emissions from artificial light and influences from moonlight. This makes it possible to take deep shots with a high signal-to-noise ratio even from highly light-polluted areas or during moonlit nights.

The filter is made of high-quality optical glass with multiple anti-reflection coatings that minimize reflections and halos. The robust 2″ aluminum mount makes it suitable for use in filter wheels and 2″ adapters. The filter works optimally with monochrome astro cameras, but can also be used with modified DSLRs and color cameras to isolate H-alpha details.

Observation goals
This filter is ideal for serious astrophotographers who want to capture emission nebulae with the highest possible contrast and detail. It works best with monochrome cameras in combination with other narrowband filters (OIII and SII) for complete narrowband shots. For visual use, this filter is unsuitable because the bandwidth is too narrow for the human eye.

Specifications

• Type: H-alpha narrowband filter
• Bandwidth: 3 nm around 656.3 nm
• Diameter: 2″ mount
• Material: Optical glass with multiple anti-reflection coating
• Mount: Aluminum
• Application:
  • ✓ Astrophotography of emission nebulae
  • ✓ High contrasts in heavy light pollution and moonlight
  • ✓ Ideal for use with monochrome cameras
  • ✗ Not suitable for visual use