2-inch Hα & [OIII] 5nm F/3.2
ToupTek Astro PureSight A1 Dual Narrowband Filter
2-inch Hα and [OIII] 5nm dual narrowband filter for emission-nebula imaging workflows.
ToupTek Astro PureSight A1 Hα & OIII Dual Narrowband Filter transmits Hα and [OIII] emission bands for deep-sky imaging workflows.
The 5nm bandpass and F/3.2 specification support use with F/3.2 optical systems while reducing out-of-band background light.
User Gallery
What Is a Dual Narrowband Filter?
A dual narrowband filter is an astrophotography filter designed to isolate specific emission wavelengths, typically hydrogen-alpha (Hα) and oxygen III (OIII).
By transmitting only these narrow spectral bands, the filter significantly enhances the visibility of emission nebulae while suppressing background light pollution from urban or suburban skies.
Dual Narrowband Filter for F/3.2 Optical Systems
ToupTek Astro PureSight A1 Hα & OIII Dual Narrowband 5nm F/3.2 Astronomical Filter is configured for F/3.2 optical systems.
The 5nm FWHM bandpasses and center wavelengths support systems at F/3.2 and slower for Hα and [OIII] signal transmission.
Anti-reflection coatings and controlled surface precision reduce internal reflections, halos, and ghosting.
Technical Parameters
| Product Name | PureSight A1 Hα & [OIII] Dual Narrowband 5nm F/3.2 |
|---|---|
| Target Emission Lines | Hα 656.3nm & [OIII] 500.7nm |
| FWHM | 5.0nm ± 1.2 / 5.0nm ± 1 |
| Transmission Rate | ≥90% |
| OD | ≥5 @ 200-1100nm |
| Substrate | Fused Silica |
| Thickness | 2.00mm ± 0.1 |
| Parallelism | ≤ 30" |
| Surface Quality | 60/40 |
| Recommended F-ratio | ≥ F/3.2 |
| Coating | IAD (Ion Deposition) |
| Size | 2-inch (frame height: 5mm, thread height: 2mm) |
| Thread | M48×0.75 |
| Frame Material | Aluminum Alloy |
| Clear Aperture | 43.9mm |
| Installation Direction | Threaded side toward the sensor |
Transmission Spectrum
ToupTek Astro PureSight A1 5nm Hα & [OIII] Dual Narrowband Filter features high transmission in both the Hα and [OIII] emission bands, while deeply blocking common light-pollution wavelengths.
Funcionalidades principais
Reduce Light Pollution with Precise Narrowband Control
The 5nm ultra-narrow FWHM bandpass isolates Hα (656.3nm) and [OIII] (500.7nm) emission lines while blocking most sources of artificial light pollution.
Nebula structure contrast
Darker background sky
Signal-to-noise support
Emission Nebula Targets
PureSight A1 is especially effective for targets such as Orion Nebula (M42), Rosette Nebula, Lagoon Nebula (M8) and Veil Nebula.
M48 Filter-Wheel Compatibility
Standard M48×0.75 thread, compatible with filter wheels and filter drawers. The 2-inch format is suitable for full-frame and smaller color astronomy cameras.
Image Purity
Optical materials and coating control
- Fused silica substrate with IAD coating for dense and uniform layers.
- Anti-reflection coatings reduce internal reflections, halos, and ghosting.
- ≥90% peak transmission, ≤30" parallelism, and 60/40 surface quality support background and star rendering.
Instalação
ToupTek Astro PureSight A1 5nm Hα & [OIII] Dual Narrowband Filter uses a threaded 2-inch installation format.
The filter comes standard with a 2-inch housing and M48×0.75 thread. During installation, please ensure that the threaded side faces the camera sensor.
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