Optolong H-alpha Filter 7nm 2 inch

Optolong Filters H-alpha 7nm 2″ is a high-quality narrowband filter that passes only the H-alpha emission line around 656.3 nm with a bandwidth of 7 nm. This isolates the red light from hydrogen-rich nebulae, while effectively suppressing interfering light pollution and other wavelengths. The result is a darker sky background and more contrasty photographs of nebulae and gas clouds.

This filter is particularly suitable for emission nebulae such as the Orion Nebula, the Rosette Nebula and the North American Nebula. Thanks to its relatively wide 7 nm bandwidth, compared to ultra narrow 3 nm filters, this filter is less critical on the telescope's f-value. This makes it versatile even with faster systems (f/4-f/5) and widescreen astrophotography.

The filter is made of high-quality optical glass with multiple anti-reflection coatings to minimize reflections and halos. The sturdy 2″ aluminum mount makes it compatible with filter wheels, 2″ eyepieces and camera adapters, making it a flexible choice for both novice and advanced astrophotographers.

Observation goals
The Optolong H-alpha 7 nm filter is ideal for astrophotography of emission nebulae with color cameras, modified DSLRs or monochrome cameras. It works effectively in light pollution and during moonlight, offering an excellent balance between high contrast and broad applicability. For visual use, the effect is limited and the filter is recommended primarily for photography.

Specifications

• Type: H-alpha narrowband filter
• Bandwidth: 7 nm around 656.3 nm
• Diameter: 2″ mount
• Material: Optical glass with multiple anti-reflection coating
• Mount: Aluminum
• Application:
  • ✓ Astrophotography of emission nebulae
  • ✓ Suitable for color cameras, DSLRs and mono cameras
  • ✓ Effective in light pollution and moonlight
  • ✗ Limited suitability for visual use