ALTAIR Ha+OIII and OIII+SII Dual Band ULTRA 6nm , 2" filter COMBO

This combo consists of two Altair Dual-Band ULTRA DualBand filters with an adjusted FWHM bandpass of 6 nm.

An individual spectrographic test report is included with each filter - another Altair first.

Available in standard 2" or 1.25" astronomical filter sizes ( the latter you can look for the article ALTAIR Ha+OIII and OIII+SII Dual-Band ULTRA 6nm filter COMBO , 1.25"" )

You will get two filters in the Combo for 2":

• DualBand 6nm Ha OIII Filter - Code F 200 DB6NM-Ha-OIII for 2"
• DualBand 6nm SII OIII filter - Code F 200 DB6NM-SII-OIII for 2" - 2" - 2" - 2" - 2" - 2" - 2" - 2"

You will get two filters in the Combo for 1.25":

• DualBand 6nm Ha OIII Filter - Code F 125 DB6NM-Ha-OIII for 1.25"
• DualBand 6nm Sii OIII filter - Code F 125 DB6NM-SII-OIII for 1.25"

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

Altair V2 coatings are very effective for LED light pollution, with a deeper blocking factor of OD>6 for wavelengths below 440 nm and OD5 for the visual range.

In a process initiated by Altair Astro, each individual filter in our certified range has an individual spectrographic test report with an actual resolution of 0.1 nm, unique to that particular filter. This is not a simulation or the overly optimistic marketing that often appears with foreign filters, such as those that are advertised with a 5 nm FWHM but actually have a 6-7 nm FWHM and have generic test reports. Rest assured that you are not playing "Chinese filter roulette".

DualBand filters transmit only the main wavelengths of emission nebulae, with near-total suppression of unwanted light, providing OD5 blocking (0.001 %) at most unwanted visual wavelengths for excellent contrast. Narrow-band bicolor imaging is a growing new trend in astrophotography, especially popular in areas with light pollution or bright moonlight. First, Altair brought you the TriBand and Quad Band filters, now we have the DualBand Ultra for the most extreme signal versus background performance.

Below is an overview of the wavelengths transmitted by the DualBand filters in this combination:

Altair DualBand 6 nm ULTRA filtertechnical specifications

• Capture two main bands of emission nebulae at the same time, per filter, while suppressing light pollution, moonlight and airglow.
• Get more data in less time by opening your imaging window, even in the summer months when it's not quite dark.
• If you have the 6 nm Sii Oiii Ultra filter and the Ha Oiii filter combination, you can capture twice as much Oiii data in each imaging session and combine them for true Hubble SHO-style imaging with a color camera.
• Extremely steep bandpass produces maximum contrast in extreme light pollution conditions: 6 nm FHWM centered on the 500.7 nm Oiii wavelength, 5.5 nm FHWM centered on the Sii and Ha wavelengths.
• Halo suppression. We have received no reports of halos caused by this filter during testing.
• Can be used with astronomical mono or CMOS One Shot Color (OSC) cameras to obtain luminance data.
• It includes UVIR blocking for modified and unmodified DSLR cameras, plus an anti-reflection coating for maximum contrast.
• Best performance is obtained at focal ratios of F4.8 or lower, although it can be used at speeds as high as F3.6, with minimal impact on contrast (conservative estimate: faster speed is possible). Like any dichroic filter, contrast increases as the focal ratio number increases.
• Available in standard 1.25" or 2" astronomical filter sizes. Filters have standard Astronomy compatible filter threads and fit inside Altair magnetic filter holders (with appropriate slider) and standard astronomical filter wheels. Choose the 2" version for use with Altair's Canon / Nikon DSLR to Astro CMOS lens adapters. For Hypercam 183C and 533C or 533M, 585C and smaller sensors, choose the 1.25" filter. For larger sensors, choose the 2" version.

Technical specifications ULTRA Altair 6nm DualBand OIII SII filter:

• *1st band, OIII CWL 500.7 nm FWHM 6 nm ~1 nm tolerance, T% 93 % 1 % tolerance.
• *2nd band, SII CWL 671.6 nm FWHM 5.5 nm ~1 nm tolerance, T% 93 % 1 % tolerance.
• OD5 blocking (0.001 %) on unwanted visual wavelengths
• 1.85 mm thick optical glass with 30 arc second parallelism. Parfocal with other Altair filters.
• Si02 "hard" top coat with UVIR blocking and anti-reflective coating for durability.

Technical Specifications ULTRA Altair 6nm DualBand OIII Ha filter:

• *1st band, OIII CWL 500.7 nm FWHM 6 nm ~1 nm tolerance, T% 93 % 1 % tolerance.
• *2nd band, Ha CWL 656.28 nm FWHM 5.5 nm ~1 nm tolerance, T% 93 % 1 % tolerance.
• OD5 blocking (0.001 %) on unwanted visual wavelengths
• 1.85 mm thick optical glass with 30 arc second parallelism. Parfocal with other Altair filters.
• Si02 "hard" top coat with UVIR blocking and anti-reflective coating for durability.