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 1.25"
Products specifications
| Technical Data | | Product size | 1.25 inches | | | | Thread type | Single thread / External thread | | | | Material | 6061T Aluminium-Extrusion | | Substrate thickness | 2.0 mm | | light aperture | 44 mm | | Central wavelengths | 500.7 nm (OIII) / 656.3 nm (H-Alpha) | | Maximum Transmission | Ø85% (OIII & H-Alpha on average) | | Bandwidth (FWHM) | 3 ± 1 nm (for both OIII and H-alpha) | | Blocking wavelength range | 300–1050 nm | | Locking depth | Average OD5 | | Surface quality | 60/40 | | Surface flatness | Transmitted wavefront PV ≤ λ/4a | | Parallelism | 30″ (arcseconds) |
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