The Optolong L1 Dual-Combo Set pairs two complementary filters for one-shot colour imaging: L-Quad Enhance, a quad-bandpass broadband LP filter that preserves natural RGB colour, and L-Para, a dual 10 nm narrowband filter that isolates Hα and OIII for high-contrast nebula detail. Use L-QEF for wide-field scenes, galaxies and clusters with balanced colour, then add L-Para data to lift emission structure — a simple OSC workflow that works from dark to suburban skies.
Includes: 1× L-Quad Enhance (quad-band broadband) + 1× L-Para (dual 10 nm narrowband).
Broadband colour + narrowband detail — capture RGB with L-QEF, enhance Hα/OIII structure with L-Para, then combine in processing.
L-Para transmission — >85% at Hα (656.3 nm) and OIII (500.7 nm) in systems of f/2 and above; anti-halo design, suitable for fast and standard optics.
L-QEF behaviour — quad-band broadband curve aimed at LP resistance while maximising preservation of RGB colour balance for galaxies, clusters and many nebulae.
Coating tech — multi-layer AR with ion-assisted deposition for durability and stable central wavelength.
Packing — two filters supplied together in one box.
Format — 2″ mounted (M48×0.75).