Ultra-narrow 3nm (H-Alpha & OIII) filter – Ideal for emission and planetary nebulae
This narrow-band filter uses multi-layer minimal-halo coating technology to minimise glare and halos. This significantly improves contrast and colour accuracy, renders sharp details against a dark background and optimises the purity of deep-sky images.The light pollution filter has been specially developed for full-frame sensors and is compatible with most standard astronomical cameras. It effectively reduces vignetting with ultra-wide-angle lenses, ensures uniform brightness from the edges to the centre of the image, and enables the full representation of nebulae and galaxies:
- Extremely narrow-band with a bandwidth of just 3 nm at H-Alpha and OIII – perfect for imaging emission and planetary nebulae.
- Minimal halo coating for the effective reduction of stray light and halos.
- Fully compatible with full-frame telescopes and cameras.
Scope of Delivery:
Dualband Filter H-Alpha/OIII 2"
Products specifications
| Technical Data | | Product Size | 2 inches | | Mirror Ring Dimensions | Φ50.8 × 7 mm | | Thread Type | Single Thread/Male Thread | | Thread Specifications | M48 × 0.75 mm | | Material | 6061T Aluminum Extrusion | | Substrate Thickness | 2.0 mm | | Light Transmission Aperture | 44 mm | | Center Wavelength | 500.7/656.3 nm | | Peak Transmittance | OIII, H-alpha average ≥85% | | Bandwidth/Full Width at Half Maximum | OIII 3±1 nm, Ha 3±1 nm | | Cutoff Wavelength | 300–1050 nm | | Cutoff Depth | Average OD5 | | Surface Quality | 60/40 | | Surface Flatness | Transmitted Wavefront PV ≤ λ/4a | | Parallelism | 30″ | | Net Weight | 12.5g |
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