Player One 2" Ha 7nm Narrowband Filter

Overview. The Player One 2" Ha 7nm Narrowband Filter is an S-series hydrogen-alpha (Hα) emission-line filter for monochrome deep-sky astrophotography with larger sensors and fast optics. It transmits a narrow 7nm ±0.5nm band centered on the hydrogen-alpha emission of nebulae while blocking the rest of the spectrum, so faint emission structure is recorded with high contrast even under moderate light pollution. The 2" format provides full illumination for larger imaging circles. The filter is built on a high-quality optical glass substrate with a multi-layer composite coating.

Who It's For. This filter suits imagers running larger-sensor monochrome cameras and 2" filter systems who want to capture emission nebulae, isolate the Hα channel of an SHO dataset, or image through moonlight and light pollution without vignetting the field.

Key Features & Design.

• Narrow 7nm passband: a 7nm ±0.5nm FWHM isolates the hydrogen-alpha line and rejects most skyglow and broadband light pollution.
• Deep blocking: OD3 blocking (less than 0.1% off-band transmission) with NIR cutoff across 700–1100nm suppresses stray light.
• High in-band throughput: approximately 90% peak transmittance preserves signal on faint targets.
• 2" clear aperture: the larger format supports bigger sensors and fast focal ratios with even illumination.
• Multi-layer composite coating: on a high-quality optical glass substrate for durable, consistent response.

Optical/Mechanical Design. The filter passes a 7nm ±0.5nm FWHM band on the hydrogen-alpha emission line and holds OD3 off-band blocking (<0.1% transmission) with the near-infrared blocked from 700–1100nm. Peak in-band transmittance is about 90%. Both surfaces are polished to 1/4 lambda surface accuracy on a 2.0 ±0.03 mm optical glass substrate carrying a multi-layer composite coating. The anodized cell uses M48×0.75 (2") threads and measures 7.5mm overall (5mm body plus 2.5mm thread).

Recommended Uses. Narrowband imaging of emission nebulae, supernova remnants, and HII regions with larger sensors; the Hα channel in bicolor (HOO) and tricolor (SHO) narrowband processing; and deep-sky capture during bright-moon or light-polluted conditions.

Compatibility & Accessory Notes. The M48×0.75 cell fits standard 2" filter wheels, drawers, and 2" threaded accessories. It pairs with matching Player One 2" OIII 7nm and SII 7nm filters for a complete SHO set. Narrowband filters are intended for monochrome imaging cameras; on one-shot-color sensors the effective throughput is reduced.

Good to Know Before You Order.

• Individual center wavelength: Player One does not publish a numeric center wavelength for this line on the product page, so it is not stated here.
• Shipping weight: a packaged weight is not published by the manufacturer; contact us if you need it before ordering.
• Camera type: narrowband results are strongest with monochrome cameras.

FAQ.

Is it difficult to set up? No. The filter threads into any standard 2" filter wheel, drawer, or threaded holder and needs no adjustment once installed.

Will it help under light pollution? Yes. The 7nm passband rejects most broadband skyglow, so Hα emission is recorded with strong contrast even from suburban skies.

Why choose 2" over 1.25"? The larger 2" format fully illuminates bigger sensors and fast optics without vignetting the corners of the field.

Bottom Line. A well-coated 7nm hydrogen-alpha filter in the larger 2" format, the Player One 2" Ha 7nm delivers high-contrast emission-line imaging across bigger sensors and forms the Hα channel of a full narrowband set.