Altair TRI-RGB Ultra Light Pollution Filter 2 Inch

Product Description

Keep your colour balance as close to real-world as possible for a truer image, whilst addressing as much light pollution as possible, with no sacrifice in OD blocking, or light transmission.

Altair TRI-RGB Ultra filters are ideal for broadband objects such as mixed emission / reflection nebulae, comets, dust clouds and galaxies. Altair TRI-RGB Ultra preserves star colour and works with fast or slow focal ratio telescopes and camera lenses.

Although primarily intended for colour CMOS cameras, the TRI-RGB can be used for luminance channel imaging with a mono camera. It also significantly increases contrast when used visually - on both deepsky objects and planets. In particular, Saturn, Jupiter and Mars.The Altair TRI-RGB Ultra filter transmits Hydrogen, Oxygen, Sulphur, and Nitrogen light bands from emission nebulae extremely well. We would argue it has the highest transmission of it's type available. High transmission peaks with steep sides enhance contrast, together with almost total suppression of unwanted light, at OD4/5 (0.01%~0.001%) over the majority of unwanted visual wavelengths.

However, importantly, it also allows enough starlight for better balancing of star colours and is not a traditional "line" filter. Therefore it includes both broadband targets AND narrowband targets.

UV and IR blocking is also included, reducing star-bloat, and enabling this filter to be used as an "enhanced luminance filter" for mono camera users.

Sensitive OSC or "One Shot Colour" CMOS cameras like the Altair Hypercam capture these peak wavelengths very efficiently, and allow them through the Bayer matrix. The filters also work with DSLRs (APS-C sensor size modified cameras are best, but normal ones will also work). When you have the complete stack of exposures, processing is relatively easy because of the large separation in colour. You can also use these filters as a "super luminance filter" for imaging nebulae with Mono cameras.

Altair TRI-RGB Ultra Filter - Technical specifications:
Altair TRI-RGB Filter Transmission Characteristics
Wavelength: & Transmission:*
Oxygen iii #1 97%
Oxygen iii #2 98%
Hydrogen Alpha 97.5%
Sulphur ii #1 98.5%
Sulphur ii #2 98.5%
* Tolerance 0.75%

OD4/5 Blocking (0.01%~0.001%) over the majority of unwanted visual wavelengths
1.85mm thick optical glass with 30 arc sec parallelism. (Parfocal with Altair filters).
Si02 "hard" overcoat with UVIR Block and Anti-Reflection Coating for durability.