Altair 2" Tri-RGB Light Pollution filter

Keep your colour balance as close to real-world as possible, whilst addressing as much light pollution as possible, with no sacrifice in OD blocking, nor in transmission! Altair TRI-RGB is great for broadband objects such as mixed emission / reflection nebulae, comets, dust clouds and galaxies, but it also allows the major emission nebulae lines through. It covers both broadband AND narrowband targets. TRI-RGB complements the Altair TriBand and DualBand filters by adding star colours. TRI-RGB and works with fast or slow focal ratio telescopes and camera lenses.  TRI-RGB is not only for light pollution control. It works very well under dark skies too by enhancing colour purity, airglow and reducing channel crossover in colour CMOS and DSLR cameras. Although primarily intended for colour cameras, TRI-RGB can be used for a cleaner luminance channel with a mono camera.  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. USA and Canadian customers - you can buy this filter direct from Land Sea and Sky or Astroworld. (Opens new window). Solar system and deepsky: TRI-RGB boosts contrast when used visually on both deep-sky 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. The high transmission enables this filter to be used on any size telescope. Altair TRI-RGB Ultra Filter - Technical specifications: Altair TRI-RGB Filter Transmission Characteristics Wavelength: Oxygen iii #1 Oxygen iii #2 Hydrogen Alpha Sulphur ii #1  Sulphur ii #2 Transmission:* 97% 98% 97.5% 98.5% 98.5% * Tolerance about 1% 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. PLEASE NOTE: Due to high demand for filter products, we sometimes temporarily suspend order to allow production to catch up. When we catch up with backorders, we will re-enable pre-ordering, or ordering. We apologize for any inconvenience. Altair and Dealers reserve the right to change product specification and price without notice.