The new Antlia 3nm Ultra Narrowband filters boost the contrast of emission nebulae and supernova remnants for professional results, even under a bright sky affected by light pollution.

The 3nm bandpass is only 1% of the entire visible spectrum increasing the signal to noise ratio delivering high contrast images and extremely dark backgrounds. To even further enhance the contrast, and suppress the stray light and internal reflections, Antlia applies edge-blackening coating on each filter.

The maximum transmission is 85% - 90% and the transmission off band is only 0.001%. This is a value often undisclosed by other filter producers although it is critical to darken the sky background and minimise the halos around the stars.

Blue-shift data shows that Antlia 3nm Pro filters can be used with nearly all systems as fast as f/3 with minimal loss in emission signal and meets the requirements of fast optics like Hyperstar and RASA.

Every filter is individually tested to ensure high the high quality standard that these filters have to meet end specifically the uniform thickness of the filter that deviate n more than ±0.05 from specifications.

Each filter cuts off the ultraviolet and infrared light so there is no need to use the IR-cut filter.

DO NOT LOOK AT THE SUN WITH THE ANTLIA FILTERS. Serious eye damage will occur.

Specifications

Passing band	3 nm (FWHM)
Glass thickness	2.0 mm ±0.05 (3.0 mm for 50 mm round & 50 x 50 mm square)
Optical flatness	1/4 λ (wavefront)
Bandpass transmission	85% - 90%
Off-band transmission	<0.001% (OD5) @ 300-1000 nm
Coating	Double-sided multilayer nano-coating
Surface quality	60/40 (in accordance with US military watch MIL-O-13830)
Parallelism	30"
Glass type	Schott monolithic optical substrate (non glued)
Filter options	Mounted 1.25", 2", Unmounted 31 mm, 36 mm, 50 mm round, 50 x 50 mm square

Gallery

Seagull Nebula by Robert Theunissen | APM LZOS 130/780, ZWO ASI2600MM Pro, Antlia 3.5nm & 3nm Ha, OIII & SII, iOptron CEM40

Tarantula Nebula - QHY268M with Antlia 3nm Pro H-alpha & OIII filters by Caleb Kam.

Crescent Nebula (NGC 6888) taken with Antlia filters by Andrea Maggi.

ANTLIA END OF YEAR 2022