Chroma SII 3nm f/3 Narrowband Filter - 50mm Round Unmounted
Chroma
SII 3nm Bandpass optimized for f/2.8-f/3.6 - 50mm Unmounted is a narrowband filter in 50mm for mono emission-line imaging.
imaging-filter midrange
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Cloud Break Optics
In stock
Specifications
Filter
- Filter type
- Single-line narrowband filter
- Filter size
- 50 mm / Unmounted
Spectral
- Passbands
- SII 672.4 nm (3 nm)
- Band count
- 1 band
- Narrowest bandpass
- 3 nm
Use
- Camera use
- Mono astronomy cameras
- Fast optics note
- Fast-optics optimized
Astrophotography Fit
Best for isolating emission lines with a mono camera and filter wheel.
SII 3nm Bandpass optimized for f/2.8-f/3.6 - 50mm Unmounted is a midrange narrowband filter (50mm).
Best for isolating emission lines with a mono camera and filter wheel.
Choose filter size around the sensor diagonal, telescope speed, and filter-wheel or drawer geometry. Flats are still required; a filter can improve contrast, but it will not rescue tilt, bad focus, or poor calibration.
Best paired with
- Monochrome camera, matching filter wheel, and autofocus offsets
- Ha/OIII/SII emission nebula projects
- Long integrations with darks, flats, and careful star handling
Not recommended for
- Unmodified color cameras as the primary workflow
- Targets dominated by broadband continuum signal
- Slower systems if the filter is a highspeed/f/2-shifted version
Where To Buy
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| Retailer | Price | Availability | View Offer |
|---|---|---|---|
| Cloud Break Optics Cloud Break Optics | $575.00 | In stock Updated 5/13/2026 | View Offer - $575.00 |