Altair SII OIII DualBand ULTRA 3.5 nm CMOS Filter with test report, 2"

Altair SII OIII DualBand ULTRA 3.5 nm CMOS Filter with test report, 2"

The Altair 3.5 nm Dual-Band ULTRA [S II] / [O III] nebula filter comes with an individual high resolution spectrographic test report.

Altair Dual Band filters allow imaging in bright moonlight and extreme light pollution as in major city centre such as London or Tokyo, with a colour CMOS camera - or in dark conditions if you want total control over your channels.

This filter transmits only the [S II] and [O III] light from emission nebulae, with almost total suppression of unwanted light, with OD6 or better (~0.0001%) over the majority of unwanted visual wavelengths.

In a process pioneered by Altair, each individual filter has an individual test report, unique to that particular filter, not a blanket test report for the whole batch like other manufacturers. Please note that these are accurate tests on a professional spectrograph at 0.1 nm resolution.

Narrowband Bi-Colour imaging is a growing new trend in astrophotography, especially popular in light polluted areas, or bright moonlight. First, Altair brought you the TriBand and Quad Band filters, now they have the DualBand Ultra for the most extreme signal vs. background performance.

Altair DualBand 3.5 nm Filter Features

Capture the two main emission nebulae bands at the same time, whilst suppressing light pollution, moonlight, and airglow.

More data in less time, opening up your imaging window, even into the summer months when it isn´t quite dark yet.

Using the Dual Band COMBO filter set you can capture twice the [O III] data, whilst obtaining [S II] to complement the Altair Ha OIII DualBand filter.

Extremely steep bandpass yields maximum contrast in extreme light pollution: 3.5 nm FHWM centred on 500.7 nm [O III] wavelength, and 3.5 nm FHWM centred on the 671.6 nm [S II] wavelength.

Halo suppression anti-reflective coating.

Can be used with One Shot Colour (OSC) CMOS and also mono astronomical cameras for luminance data.

Includes UVIR blocking for both modified and un-modified DSLR cameras.

The 2" filter has standard M48x0.75 thread, and fits inside the Altair Magnetic Filter holders, standard 2" filter wheels, plus the Altair Canon / Nikon DSLR lens to astro CMOS adaptors.

How do OSC narrowband filters work?

Altair OSC narrowband filters work by isolating the primary nebulae emission zones in the red and blue wavelengths, and separating them into two main "zones" with a wide separation for easy capture with a colour camera - all in one exposure! Not only is capture more convenient with one filter, but processing is easy too, thanks to the wide separation of the green/blue and red "zones". Light pollution control is extremely effective and LED light is also significantly reduced.

- Dual band filter

Safety informations: PDF Download