ANTLIA ALP-T SII & Hb 3.5nm DUAL BAND FILTER
Antlia
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ANTLIA ALP-T SII & Hb 3.5nm DUAL BAND FILTER is backordered and will ship as soon as it is back in stock.
The new Antlia ALP-T Golden S-II and H-beta 3.5nm Dual Band filter is specifically designed for astrophotography with colour DSLR, CMOS or CCD cameras in areas with heavy light pollution. Its two 3.5nm passing bands are exceptional at isolating nebulae emissions in SII and Hb. Images taken through this filter can be easily combined with those taken through the Ha & OIII ALP-T to create stunning full-colour Hubble Palette pictures.
Currently this filter is only available in 2" mounted.
The optical density of 4.5 suppresses unwanted wavelengths from light pollution, moonlight and skyglow, resulting in superior signal-to-noise ratio and better contrast.
Like all Antlia filters, the Golden Dual Band filter has excellent halo suppression, making imaging of targets surrounded by bright stars such as the Horsehead Nebula pain-free.
- It blocks the artificial light from mercury vapour lamps, both high and low pressure sodium vapour lights and the unwanted natural light caused by neutral oxygen emission in our atmosphere (i.e. skyglow).
- Maximum transmission of the main nebula emission lines at SII (672.4nm) is >90% and H-beta (486.1nm) is >85%. Good signal is still achievable with optics as fast as f/3.
- Two transmission bands with a bandpass of 3.5nm. OD4.5 @ 300-1100nm.
- Ideal for urban areas with extreme light pollution.
- It incorporates an IR/UV-Cut filter that is necessary in astrophotography, especially for astronomy cameras that are sensitive to the infrared radiation.
- Ultra-thin filter cell to maximise the compatibility with most filter drawers.
- Ideal flat-top and moderate bandpass reduces spectrum down shifts.
- Data taken with this filter can be combined with that taken with the ALP-T H-alpha & OIII filter to create Hubble Palette images.
To even further enhance the contrast, and suppress the stray light and internal reflections, Antlia applies edge-blackening coating on each filter. Each filter is individually tested to ensure a high quality standard. The tight tolerance of the filters substrate assure a maximum deviance of ±0.05 from specifications making these filters parfocal.
DO NOT LOOK AT THE SUN WITH ANTLIA FILTERS. Serious eye damage will occur.
Specifications
Passing band | 3.5 nm +0.5 / -0.5 nm (FWHM) |
Glass thickness |
2.0 mm ±0.05 |
Optical flatness |
1/4 λ (wavefront) |
Bandpass transmission | H-a >90%, OIII >85% |
Off-band transmission | OD4.5 @ 300-1100 nm |
Coating | Double-sided multilayer nano-coating |
Surface quality | 60/40 (in accordance with US military watch MIL-O-13830) |
Parallelism | 30" |
SKU |
2" - AN-ALP-T2-HbSII-3nm |