Περιγραφή
Askar ColourMagic Ultra E1 2″ Duo-narrowband Filter (Hα + O-III) is a professional astrophotography filter with ultra-narrow transmission bands. It has been designed specifically for recording emission nebulae, planetary nebulae and supernova remnants. The unique “Ultra” design provides excellent halos control – one band is 3.7 nm wide, the other 4.0 nm wide . Thanks to this, the filter effectively eliminates the influence of sodium lamps, LEDs and atmospheric glow, allowing you to obtain high quality images even in strongly lit areas.
Key Features of the Ultra E1 Filter
• two ultra-narrow transmission bands: Hα 656.6 nm (FWHM 3.7 nm) and O-III 500.7 nm (FWHM 4.0 nm)
• peak transmission > 85% – high efficiency of light collection of emission lines
• suppression of the remaining spectrum ≥ OD5 (200 – 1100 nm) – effective blocking of light pollution
• ideal for color astronomy cameras – one filter is enough to separate Hα and O III
• minimal halos and reflections thanks to special coating optimization
• 2″ frame (M48×0.75) – compatible with most filter wheels and drawers
Set components
• ColourMagic Ultra E1 2″ duo-narrowband filter
• protective transport case
Technical parameters
• central wavelengths: 500.7 nm (O III) / 656.6 nm (Hα)
• FWHM: 4.0 nm ± 0.3 nm (O III) / 3.7 nm ± 0.3 nm (Hα)
• peak transmission: ≥ 85%
• out-of-band attenuation: ≥ OD5 (200 – 1100 nm)
• glass thickness: 1.85 ± 0.05 mm
• surface quality: 60/40
• parallelism: 30″
• diameter and thread: 2″ (M48×0.75)
• manufacturer: Askar – China
The ColourMagic Ultra E1 filter is a practical and efficient tool for colour astrophotographers who want to capture nebula structures in highly illuminated locations without the need to use several separate narrowband filters.
