Optolong IR Pass 685nm Filter - 2" Mounted
Optolong
Optolong IR Pass 685nm Filter - 2" Mounted is a narrowband filter in 2" for mono emission-line imaging.
imaging-filter budget
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Specifications
Filter
- Filter type
- Infrared pass filter
- Filter size
- 2" / Mounted
Spectral
- Passbands
- IR pass 685 nm
- Band count
- 1 band
Specifications
- Thickness
- 1.85 mm
- Substrate / coating
- B270 optical glass
Use
- Camera use
- Color or mono astronomy cameras, depending on target and workflow
Astrophotography Fit
Best for isolating emission lines with a mono camera and filter wheel.
Optolong IR Pass 685nm Filter - 2" Mounted is a budget-friendly narrowband filter (2").
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
- Users who want natural star color with minimal processing
Where To Buy
Some links on this page are affiliate links. Prices and availability are pulled automatically from each retailer and updated daily.
| Retailer | Price | Availability | View Offer |
|---|---|---|---|
| High Point Scientific High Point Scientific | $129.00 | In stock Updated 5/12/2026 | View Offer - $129.00 |
| Starizona Starizona | $129.00 | Out of stock Updated 5/13/2026 | View Offer - $129.00 |