Antlia NII 3nm Pro Narrowband Filter - 2'' Mounted

The Antlia NII Pro narrowband filter optimizes the full width at half maximum (FWHM) to a 3nm bandpass. As the bandwidth narrows, these 3nm Pro narrowband filters enhance the contrast of emission targets by effectively reducing unwanted background signals. Designed to achieve an impressive 88% transmission at the 654.8nm line, Antlia NII 3nm Pro filters provide maximum signal and well-defined nebula structures. The out-of-band blocking specification is rated at OD5 (0.001%), ensuring excellent signal-to-noise ratio (SNR) and effective cutoff rates to minimize interference from other wavelengths. These improved sharp cutoff astrophotography 3nm Pro filters are specifically engineered to reduce halos around bright stars.

The main features and application

High transmittance and smallest bandwidth to maximize contrast

Steep spectral profile minimizes halos around bright stars

A single substrate to eliminate internal reflections   

Narrowband Objects: NII Emission Nebulae

Use in light polluted areas and dark sites

Extend imaging time when the moon is up

All Antlia narrowband Pro filters can be used down to f/3 with minimal loss of signal

All Antlia Narrowband filters unmounted are edge blackened to eliminate internal reflections from stray light

Superior optical reliability reduces post image processing

This filter is only effective for deep sky objects that contain NII emissions

Technical Specifications:

Spectrum Curve:

Warranty: 3-years against delamination

Available Size：

Mounted 2''

Filter Ring:

2’’ (M48*0.75)

Ultra-thin filter cell to minimize vignetting by maximize possible clear aperture

Black Anodized Finish

Laser Engraving No Fading

Not Recommended:

Solar imaging

Night visual observation

Not Permitted:

DO NOT LOOK AT THE SUN WITH THIS FILTER DIRECTLY

Serious eye damage will result if you fail to observe the warning.