Gear Database

Antlia 2.5nm Narrowband Oxygen III (OIII) Ultra Filter - 2" Mounted

Antlia

Antlia 2.5nm Narrowband Oxygen III (OIII) Ultra Imaging Filter - 2" Mounted is a narrowband filter in 2" for mono emission-line imaging.

imaging-filter midrange
Antlia 2.5nm Narrowband Oxygen III (OIII) Ultra Filter - 2" Mounted

Best Current Offer

Starizona logo
Starizona
In stock
$649.00

Specifications

Filter

Filter type
Single-line narrowband filter
Filter size
2" / Mounted

Spectral

Passbands
OIII 500.7 nm (2.5 nm)
Band count
1 band
Narrowest bandpass
2.5 nm

Specifications

Transmission
92%
Thickness
2 mm

Use

Camera use
Mono astronomy cameras

Astrophotography Fit

Best for isolating emission lines with a mono camera and filter wheel.

Antlia 2.5nm Narrowband Oxygen III (OIII) Ultra Imaging Filter - 2" Mounted is a midrange 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

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Retailer Price Availability View Offer
Starizona logo
Starizona
Starizona
$649.00
In stock
Updated 5/12/2026
View Offer - $649.00