The new Antlia Triband RGB Ultra 2" filter is a broadband filter specifically designed for astrophotography with colour DSLR, CMOS or CCD cameras in areas with heavy light pollution. Three passbands in the red, green and blue allow imaging of all deep sky targets such as galaxies, star clusters and reflection nebulae.
The Triband RGB Ultra filter has a balanced colour transmission so that objects are captured accurately. The quantum efficiency of current CMOS sensors is often quite low in the blue end of the spectrum, so most broadband light pollution filters do not render a balanced image. To address this, Antlia has designed this filter to increase the luminous flux of the blue channel while retaining good OIII and H-beta transmission.
Witch Head Nebula at f/2 by Greg England | Antlia Triband filter, RASA 8", 24 x 300 seconds.
The Triband RGB Ultra filter can be used with telescopes as fast as f/2 with minimal band-shifting. The optical density of 4 suppresses unwanted wavelengths from light pollution, moonlight and skyglow, resulting in superior signal-to-noise ratio and better contrast.
- 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 >92%.
- 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.
- Can be used as a luminance filter with monochrome cameras.
- Ultra-thin filter cell to maximise the compatibility with most filter drawers.
- Ideal flat-top and large bandpass reduces spectrum down shifts.
- Good performance at focal ratios slower than f/2.
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.
2.0 mm ±0.05
1/4 λ (wavefront)
|Transmission at H-a, S-II, O-III, NII
|OD4 @ 300-1100 nm
|Double-sided multilayer nano-coating
|60/40 (in accordance with US military watch MIL-O-13830)
Performance of this filter on the RASA 8 is very good, as good as the Celestron branded LPF but a fraction of the cost.
I saw no gradient in the 300 sec subs taken in a bottle 4 sky looking towards Hobart.
Results look very promising and I am glad I made the decision to purchase this filter.