Altair Ha Oiii DualBand 6nm Certified CMOS Filter 2 Inch with Test Report

Product Description

Altair Dual-Band ULTRA Ha / Oii narrowband filter with a tight 6nm FWHM Bandpass.

Altair V2 coatings are very effective for LED light pollution, with a deeper blocking factor of OD>6 for wavelengths below 440nm, and OD4.5 for the visual range.

Based on an average sample of 90 filters tested, the Bandwidth at FHWM for Oiii is 6nm with 93% transmission, and the FWHM for Ha is 5.5nm with 93% transmission. Tolerances are 0.5nm and 0.5% respectively.

This is the filter for imaging in moonlight or light pollution with a colour CMOS camera - or even in dark-sky conditions if you want total isolation and control over your channels, narrowband-style.

In a process pioneered by Altair, each individual filter in our certified range has an individual spectrographic test report, unique to that particular filter. Not a simulation, nor the overly optimistic marketing you tend to get with foreign filters, such as those advertised at 5nm FWHM but which actually have 6-7nm FWHM, and which do not have individual test reports.

The DualBand Ha/Oiii filter transmits only the Ha and Oiii light from emission nebulae, with almost total suppression of unwanted light, with OD4/5 (0.01%~0.001%) over the majority of unwanted visual wavelengths. 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 we have the DualBand Ultra for the most extreme signal vs. background performance.

Altair DualBand 6nm 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. Capture twice the Oiii data, whilst obtaining Sii to complement the Altair Ha Oiii DualBand filter.
Extremely steep bandpass yields maximum contrast in extreme light pollution: 6nm FHWM centred on 500.7nm Oiii wavelength, and 5.5nm FHWM centred on the 656.28nm Ha wavelength.
No halos. We have not had any reports of halos caused by this filter in testing and we don't expect any with these new special coatings.
Can be used with One Shot Colour (OSC) CMOS or mono astronomical cameras for luminance data.
Includes UVIR blocking for both modified and un-modified DSLR cameras, plus an anti-reflection coating for halo suppression. To see the AR coating in action, please see images demonstrating the same filter with and without the AR coating on the bright star, Capella in exactly the same conditions with the same settings.
Best performance at focal ratios as fast as F4.8, with contrast increasing as focal ratio increases.
The 2" filter has standard M48x0.75mm thread, and fits inside the Altair Magnetic Filter holders, standard 2" filter wheels, plus the Altair Canon / Nikon DSLR lens to astro CMOS adaptors.

Altair 6nm DualBand ULTRA Filter Specifications:
*1st band, Oiii CWL 500.7nm FWHM 6nm ~0.5nm tolerance , T% 93% 0.5% Tolerance.
*2nd band, Ha CWL 656.28nm FWHM 5.5nm ~0.5nm tolerance, T% 93% 0.5% Tolerance.
OD4/5 Blocking (0.01%~0.001%) over the majority of unwanted wavelengths
1.85mm thick optical glass with 30 arc sec parallelism.
Si02 "hard" overcoat with UVIR Block and Anti-Reflection Coating for durability.